Give the starting value a, the growth factor b, and the growth rate r if Q = abt = a(1 + r)t Write r as a percent. Q = 1750 (1.593) Superscript t a. a = 1750 b = 1.593 r = 0.593% c. a = 2787.75 b = 2.5376 r = 0.593% b. a = 1750 b = 1.593 r = 59.3% d. a = 2787.75 b = 1.593 r = 59.3%

Answers

Answer 1

Answer:

Option b.

Step-by-step explanation:

If the starting value a, the growth factor b, and the growth rate r, then

[tex]Q=ab^t=a(1+r)^t[/tex]        ...(1)

It is given that

[tex]Q=1750(1.593)^t[/tex]        ...(2)

On comparing (1) and (2), we get

[tex]a=1750, b=1.593[/tex]

Now, equation (2) can be rewritten as

[tex]Q=1750(1+0.593)^t[/tex]        ...(3)

On comparing (1) and (2), we get

[tex]r=0.593[/tex]

[tex]r=(0.593\times 100)\%[/tex]

[tex]r=59.3\%[/tex]

Therefore, the correct option is b.


Related Questions

air flows through a duct at 2400 cubic feet per minute after several feet in a few vent the air flow decreases to 1680 cubic feet what is the percent drop that has occurred ​

Answers

Answer:

I think the answer is 7.2%

Step-by-step explanation:

2400-1680=720

720/100=7.2

7.2 is the answer

Hope this helps!

Which of the following are identities?

Answers

Answer:

A. III only

Step-by-step explanation:

In mathematics, an identity is one of the characteristics of algebraic expressions.

Given variable a and b in an algebraic expression, an identity is defined as an equality that remains the same no matter the values that we choose for either variable a or b.

Identity in mathematics makes it very easy to solve algebraic expressions. The two sides of an identity in an algebra can easily be exchanged for each other.

In the above question, we are given 3 Options.

I) 3(5 + 2x) = 15 + 6x

II) y = x + 3

III) (x² - y²) = (x + y) (x - y)

Option I) 3(5 + 2x) = 15 + 6x

Is showing distributive property in mathematics.

Distributive property is :

a(b + c) = ab + ac

Option I is not an identity , therefore it is wrong.

Option II) y = x + 3 is just an algebraic expression.

Only Option III is an identity. This is because it follows the rule of

(a² - b²) = (a + b) (a - b)

We can prove and confirm this be solving the algebraic expression

(x + y) (x - y)

We expand the bracket

x² - xy +xy - y²

x² - y²

Therefore, option A is the correct option.

(NEED HELP ASAP)Determine whether the situation calls for a survey, an observational study, or an experiment. You want to find new car buyers' opinions on the most important options. Question 7 options: survey observational study experiment

Answers

Answer: The answer is "experiment."

Step-by-step explanation:

This procedure is being used in order to validate a hypothesis, particularly in a research study. In the situation above, you have to validate whether a new reading program can increase reading comprehension or not.

The experiment consists of independent, dependent, and controlled variables. The independent variables are the ones being changed by the researcher, while the dependent variables tell whether the changes in the independent variable is significant. The controlled variables are the ones that are constant.

The dependent variable above is reading comprehension, while the new reading program is the independent variable. Examples of controlled variables are the ages of the participants. The age directly affects the reading comprehension, thus it has to be considered.

Lina is making a trail mix of a hiking trip. She has 2 1/2 cups of peanuts, 3 1/4 cups of raisins, and 2 2/3 cups of banana chips. How many cups of trail mix can she make? Please answer this if you want too.

Answers

Answer: 8 cups of trail mix

Step-by-step explanation: Convert 2 1/2, 3 1/4, and 2 2/3 to decimals—2.5, 3.25, and 2.67. Then add them together to get 8.42. You need to round to 8, because you can only have a exact numbers of cups.

Hope this helps:)

can someone simplify (3x)^4

Answers

Answer:

81x^4

Step-by-step explanation:

Apply the product rule to 3x

3^4x^4

Raise 3  to the power of  4

81x^4

please mark me brainliest!

Please help with this

Answers

Answer:

5/2

Step-by-step explanation:

We take the ratio of a side of ABC over the same side on DEF

AB/ DE

35/14

Divide top and bottom by 7

5/2

Which statement best describes Cheryl's commute? A. Cheryl accelerated to 65 mph, made a stop for 5.5 minutes, and then decelerated to 45 mph. B. Cheryl drove at a speed of 65 mph for 1 minute, drove at a constant speed for 5.5 minutes, and then drove at a speed of 45 mph for 2.5 minutes. C. Cheryl accelerated to 65 mph, drove at a constant speed for 5.5 minutes, and then decelerated to 45 mph. D. Cheryl drove at a speed of 65 mph for 1 minute, made a stop for 5.5 minutes, and then drove at a speed of 45 mph for 2.5 minutes.

Answers

Answer:

C. Cheryl accelerated to 65 mph, drove at a constant speed for 5.5 minutes, and then decelerated to 45 mph.  

Step-by-step explanation:

Assume the graph of Cheryl's commute was like the one below.

We see that she started at 0 mph.  

One minute later, she was up to 65 mph, so she had accelerated (increased her speed).

At 6.5 min (5,5 min later) her speed was still 65 mph, so she was driving at a constant speed.

Over the next 2.5 min, her speed dropped to 45 mph, so she was decelerating.

 

Answer:

D

Step-by-step explanation:

on Edmentum

The length of a square is 10 cm. Calculate the perimeter of the square A. 40cm² B. 400cm² C. 4ocm D. 414cm² I will mark you as brainliest

Answers

Answer:

40 cm

Step-by-step explanation:

the 414cm2 is eso they

True or false? It's possible to create a regular tessellation with a regular octagon.

Answers

The answer should be False

It is possible to create a regular tessellation with a regular octagon, is false.

What is regular tessellation?

A tessellation or tiling is the seamless covering of an area, frequently a flat, including one or much more geometric forms, known as tiles.

It is impossible to create a regular tessellation with a regular octagon because when an octagon is arranged, a gap is there.

Then the statement is false.

More about the regular tessellation link is given below.

https://brainly.com/question/12926513

#SPJ2

A store sells 3 categories of kitchen items: cups, bowls, and spoons. There are 5 types of cups, 4 types of bowls, and 2 types of spoons. How many different combinations can you buy in this store of: A set of a bowl, cup, and spoon

Answers

40 is the answer because 5 times 4 times 2

HELP PLEASE!!! I need your guys help on this question.

Answers

Answer:

Area of a trapezium = 1/2(a+b)×h

where a and b are parallel sides of the trapezium

h is the height

First question

We must first find the height of the trapezium using Pythagoras theorem

That's

h² = 8² -3²

h =√ 64 - 9

h = √ 55m

a = 7m

b = 10+3 = 13m

Area of the trapezoid = 1/2(7+13)×√55

= 1/2×20×√55

= 74.16

= 74m² to the nearest tenth

Second question

We use sine to find the height

sin30° = h/12

h = 12 sin 30°

h = 6 in

Let the other half of the parallel side be x

To find the other half of the parallel side we use Pythagoras theorem

That's

x² = 12²- 6²

x = √144-36

x = √108

x = 6√3 in

So for this trapezoid

a = 9 in

b = (9 + 6√3) in

h = 6 in

Area of the trapezoid = 1/2(9 + 9+6√3) × 6

= 1/2(18+6√3)×6

= 85.176 in²

= 85 in² to the nearest tenth

Hope this helps you

Answer:

The first (left) trapezoid's area is [tex]10\sqrt{55}[/tex]m or ≈ 74.2m²

The second (right) trapezoid's area is [tex]54 +18\sqrt{3}[/tex] or ≈ 85.2 in²

Step-by-step explanation:

First trapezoid (left):

Because the first trapezoid is a normal trapezoid, we can use the equation [tex]A = \frac{a+ b}{2} * h[/tex] Where a is equal to one base length and b is equal to the other base length and h is the height of the trapezoid.

a = 7

b = 13

h = [tex]\sqrt{55}[/tex]   ([tex]3^{2}+h^{2} = 8^{2}[/tex])

Plug into the equation:

[tex]A = \frac{7+13}{2} *\sqrt{55}[/tex]

A = [tex]10\sqrt{55}[/tex] or ≈74.2m²

Second trapezoid (right):

Not a normal trapezoid (split into a triangle and a square)

Let's solve for the triangle first:

using [tex]sin(30) = \frac{x}{12}[/tex] to find the right-hand side of the triangle we get x = 6

because this is a 30 60 triangle, the last side has to be [tex]6\sqrt{3}[/tex]

Now we can calculate the area of the figure:

Triangle is [tex]\frac{1}{2} * 6 * 6\sqrt{3} = 18\sqrt{3}[/tex]

Rectangle is 6 * 9 = 54

Area = [tex]54 +18\sqrt{3}[/tex] or ≈ 85.2 in²

Please help me asap!!!!!?

Answers

Answer:

D

Step-by-step explanation:

the scale factor will be the square of the fraction

7/4 =49/16

Answer:

D

Step-by-step explanation:

PLEASE HELP! 10 POINTS!The graphs of f(x) and g(x) are shown below:
What are the solutions to the equation f(x) = g(x)?
Ox= -3,4
x = -4.2.5
X = -0.8, 2.5
X = 8.-8

Answers

Answer:

x = -4, 2.5

Step-by-step explanation:

To find the solution, look for the points where the line crosses the parabola. As this question only asks for the x-values, find the distance to the left and right of the y-axis. Here, it's -4 on the left and 2.5 on the right.

- 2x
f(x)= x +4,
4x - 7
XS-10
- 10 X2
20. Use the piecewise function to evaluate points f(-1), f(2), and f(12).
O A. f(-1) = 3, f(2) = 1, and f(12) = 41
B. f(-1) = 3, f(2) = 6, and f(12) = 41
O C. f(-1) = 2. f(2) = 1, and |(12) = 41
D. f(-1) = 2. f(2) = 6, and f(12) = 41

Answers

Answer:

[tex]f(-1) = 3[/tex]

[tex]f(2) = 6[/tex]

[tex]f(12) = 41[/tex]

Step-by-step explanation:

Given

The piece wise function can be split to:-

[tex]f(x) = -2x[/tex]   [tex]x\leq -10[/tex]

[tex]f(x) = x + 4[/tex]   [tex]-10<x\leq 2[/tex]

[tex]f(x) = 4x - 7[/tex]   [tex]x> 2[/tex]

Required

f(-1), f(2) and f(12)

To solve for each of these functions, we first check the range they fall into, then we execute the corresponding function

Solving f(-1)

-1 is within the range of [tex]-10<x\leq 2[/tex]

Hence; we make use of [tex]f(x) = x + 4[/tex]  

Substitute -1 for x

[tex]f(-1) = -1 + 4[/tex]

[tex]f(-1) = 3[/tex]

Solving f(2)

2 is within the range of [tex]-10<x\leq 2[/tex]

Hence; we make use of [tex]f(x) = x + 4[/tex]  

Substitute 2 for x

[tex]f(2) = 2 + 4[/tex]

[tex]f(2) = 6[/tex]

 

Solving f(12)

12 is within the range of [tex]x> 2[/tex]

Hence; we make use of [tex]f(x) = 4x - 7[/tex]  

Substitute 12 for x

[tex]f(12) = 4(12) - 7[/tex]  

[tex]f(12) = 48 - 7[/tex]

[tex]f(12) = 41[/tex]

If d = the number of dogs, which variable expression represents the phrase below? the sum of the number of dogs and the 6 cats.

Answers

Answer:

D.

Step-by-step explanation:

" Sum" means "+".

The sum of the number of dogs and the 6 cats.

d + 6

Answer:

Option D

Step-by-step explanation:

Sum is Adding (+)

So,

The expression becomes

=> d+6

Find the smallest number by which 8788 must be multiplied so that the quotient is a perfect cube. Also, find the cube root of the perfect cube so obtained.​

Answers

Answer:

Hi ,

Cube of a number :

_______________

For a given number x we define cube

of x = x × x × x , denoted by x^3.

A given Natural number is a perfect

Cube if it can be expressed as the

product of triplets of equal factors.

Now ,

Write given number as product of

prime .

8788 = 2 × 4394

= 2 × 2 × 2197

= 2 × 2 × 13 × 169

= 2 × 2 × 13 × 13 × 13

= 2 × 2 × ( 13 × 13 × 13 )

Here we have only triplet of equal

factors i.e 13

To make 8788 into perfect Cube we

have multiply with 2.

Now ,

2 × 8788 = ( 2 × 2 × 2 ) × ( 13 × 13 × 13 )

17576 = ( 2 × 13 )^3 = ( 26 )^3 perfect

Cube

I hope this will useful to you.

Owners of a recreation area are filling a small pond with water. Let y represent the total amount of water in the pond (in liters). Let x represent the total number of minutes that water has been added. Suppose that x and y are related by the equation y=400+32x . Answer the questions below. Note that a change can be an increase or a decrease. For an increase, use a positive number. For a decrease, use a negative number. What is the change per minute in the amount of water in the pond? What was the starting amount of water in the pond?

Answers

Answer:

32400

Step-by-step explanation:

Lets start by defining the numbers in the equation.

This  equation is in slope-intercept form meaning that it is y=mx+b or y = b+mx they are both the same

In slope-intercept form,

m = slope or rateand b = y-intercept

Th equation is y=400+32x so now we know

b=400and m=32

For the first question the change per minute is the rate so it is 32.

For the second question the starting amount is the same as the y-intercept so it is 400.

Find the volume of a sphere 8 feet in diameter use 3.14 round your answer to the nearest tenth

(A) 150.7
(B) 267.9
(C) 83.7
(D)67.0

What one is it help me please

Answers

Answer:

B 267.9

Step-by-step explanation:

the formula is again the same, so you plug 4 in (because the radius is half the diameter) and solve to get around 267.9

Which of the following list of ordered pairs is a function?

Answers

Answer:

C

Step-by-step explanation:

A. (4, 0) and (4, 3) have the same x coordinate (Can't happen in a function).

B. (2, 5) and (2, 1) have the same x coordinate.

C. It passes the vertical line test on a graph and no x is repeated.

D. (2, 3) and (2, 5) share the same x coordinate.

Answer:

c is correct answer.

a function from set A (x coordinate) to set B (y coordinate) a special type of relation defined from set A to set B if every element of set A is mapped with unique element of set B.

Please help :) Is the relationship shown by the data linear? If so model the data with an equation.

Answers

Answer:

y-5=5/4(x-1)

Step-by-step explanation:

the slope is 1.25

m=y2-y1/x2-x1=10-5/5-1=5/4=1.25

y-5=(5)/(4)(x-1)=

y=(5)/(4)x+(15)/(4) this one is linear

it is a linear function and the

10 rubber stamps cost $10.30 Which equation would help determine the cost of 2 rubber stamps?

Answers

10.30/10 = 1.03 per stamp 1.03 x 2 = $2.06 for two

Answer:
$2.06
Rounded:
$2.00

The cost of 2 rubber stamps is $2.

We have given that rubber stamps cost $10.30  

we have determined the cost of 2 rubber stamps.

We have to find the price per stamp.

What is the formula for the value price of one stamp?

[tex]1 samp price=\frac{cost for all stamp }{total number of stamp}[/tex]

Therefore we get,

10.30/10 = 1.03 per stamp

For two stamps:

1.03 x 2 = $2.06 for two

=$2.06

=$2

To learn more about the cost visit:

https://brainly.com/question/19104371

A researcher posts a newspaper advertisement offering 520 in exchange for participation in a short study. The researcher accepts the first five people who respond to the advertisement which
of the following statements is true about the sample?
It is not a valid sample because it is only a short study
It is a valid sample because money was offered to participants
It is a valid sample because the first five people were selected to participate
It is not a valid sample because it is not a random sample of the population

Answers

Answer:

It's a valid sample because the first five people were selected to participate.

Step-by-step explanation:

True because random people who saw the advertisement responded. By chance, not every person who saw the advertisement answered, therefore it was random, but it would be more random if he decided to reject the second, fourth, sixth, and eighth person, and only the first, third, fifth, seventh, and ninth were chosen.

What is the standard form of this function? f(x) = -(x − 4)2 + 2 A. f(x) = -x2 + 4x − 30 B. f(x) = x2 + 8x − 14 C. f(x) = -x2 + 8x − 14 D. f(x) = x2 + 4x − 30

Answers

Answer:

C

Step-by-step explanation:

Standard form is f(x) = ax² + bx + c.

f(x) = -(x - 4)² + 2

= -(x² - 8x + 16) + 2

= -x² + 8x - 16 + 2

= -x² + 8x - 14

Hi,

the correct answer is C

This is the correct equation: f(x) = -x^2 + 8x - 14

XD

P.S. (on the image I sent the answer was B but on your test the correct one is C. The equation is still the same.)

What is the volume of a cylinder with a height of 17 cm and a base radius of 7 cm to the nearest 10th

Answers

Answer:

Step-by-step explanation:

volume =πr²h=π×7²×17≈2616.9 cm³

The volume of a cylinder is 2616.95 cubic centimeters.

What is volume?

It is defined as a three-dimensional space enclosed by an object or thing.

We have:

The height of the cylinder h = 17 cm

Base radius of the cylinder r = 7 cm

We know the volume of a cylinder is given by:

[tex]\rm V = \pi r^2h[/tex]

[tex]\rm V = \pi\times 7^2\times17[/tex]

V = 833π cubic centimeters

V = 833×3.141592

V = 2616.94668 cubic centimeters or

V = 2616.95 cubic centimeters.

Thus, the volume of a cylinder is 2616.95 cubic centimeters.

Learn more about the volume here:

https://brainly.com/question/16788902

PLEASE ANSWER ASAPPPPPP! What is the quotient of 6 and -1/2.

Answers

Answer:

-12

Step-by-step explanation:

6 ÷ -1/2

Copy dot flip

6 * -2/1

-12

Find the measures of the angles of the ∆ABC if m∠A : m∠B : m∠C = 2:3:4.

Answers

Answer:

m∠A = 2x = 2*20 = 40

m∠B = 3x = 3*20 = 60

m∠C= 4x = = 4*20 = 80

Step-by-step explanation:

we know sum of angles of triangle is 180 degrees

given

m∠A : m∠B : m∠C = 2:3:4

let the angle be

m∠A = 2x

m∠B = 3x

m∠C= 4x

we have taken such angle by applying rule of indices where

a:b:c = ax:bx:cx

which means that if we multiply all term of ratio by same number ratio remains same

thus,

2x+3x+4x = 180

9x = 180

x = 180/9 = 20

Thus,

m∠A = 2x = 2*20 = 40

m∠B = 3x = 3*20 = 60

m∠C= 4x = = 4*20 = 80

a. 1620
b. 180
c. 38
d. 29

Answers

Answer:

V =1620 pi  cm^2

Step-by-step explanation:

The volume of a cylinder is given by

V = pi r^2 h

V = pi ( 9)^2 * 20

V =1620 pi  cm^2

A)x 1/9
B)x 1/6
C)x^6
D) x^9

Please explain in simple terms how you would solve this please!!

Answers

Answer:

Answer should be x^9

Step-by-step explanation:

This equation looks really complicted, but it's actually much easier when you break it down! First, your going to multiply the fraction 3/2 by 6 - since one is a fraction, youre going to find the GCF, or Greatest Common Factor, and reduce it. The GCF in this equation is 2, so we eliminate the two from the fraction (making it just 3) and divide 6 by 2 (getting 3). Thus, we are left with (x^3)^3 -> 3 x 3 = 9. So we are left with x^9. I hope this helps!

Rectangle ABCD is graphed in the coordinate plane. The following are the vertices of the rectangle: A(2, -3), B(4, -3), C(4,5), and D(2,5) What is the perimeter of rectangle ABCD

Answers

Answer:

20

Step-by-step explanation:

(2,-3) to (4,-3) = 2

(4,-3) to (4,5) = 8

(4,5) to (2,5) = 2

(2,5) to (2,-3) = 8

Total =20

Answer:

20

Step-by-step explanation:

khan said so trust me

Need help with this question please:

Answers

Answer:

If the data is collected in a biased manner, or the number of observations is too small, the graph could be skewed. To ensure the data is not skewed, collect a large representative unbiased sample. Hope this helps

Step-by-step explanation:

Other Questions
Compare the distributions using either the means and standard deviations or the five-number summaries. Justify your choice. Set A Set B The distributions are symmetric, so use the means and standard deviations. The mean for Set A is about 44.6 with standard deviation of about 6.2. The mean for Set B is about 42.8 with standard deviation of about 1.86. While the average low temperatures for the cities are approximately equal, the greater standard deviation for Set B means that Set As low temperatures have a greater variability than Set B temperatures. The distributions are symmetric, so use the means and standard deviations. The mean for Set B is about 41.56 with standard deviation of about 6.07. The mean for Set A is about 43.8 with standard deviation of about 14.8. While the average low temperatures for the cities are approximately equal, the greater standard deviation for Set A means that Set As low temperatures have a greater variability than Set B temperatures. The distributions are symmetric, so use the means and standard deviations. The mean for Set A is about 44.6 with standard deviation of about 6.4. The mean for Set B is about 41.5 with standard deviation of about 6.7. While the average low temperatures for the cities are approximately equal, the greater standard deviation for Set B means that Set Bs low temperatures have a greater variability than Set A temperatures. The distributions are symmetric, so use the means and standard deviations. The mean for Set A is about 44.6 with standard deviation of about 6.2. The mean for Set B is about 43.8 with standard deviation of about 14.8. While the average low temperatures for the cities are approximately equal, the greater standard deviation for Set B means that Set Bs low temperatures have a greater variability than Set A temperatures. What is 62 in expanded form?A. 2 x 2 x 2 x 2 x 2 x 2 B. 6 x 6 C. 12 D. 36 The key schedule results in generating multiple keys from the one secret key. These multiple keys are used: a. in multiple sessions of communications one after the other. For example, if someone has 12 keys, they can use it for twelve video calls one after the other. b. such that one of them is picked up at random at a time. c. some as private keys, some as public keys. d. for different rounds of encryption for the same plaintext to strengthen the cipher. Which shapes have the same volume as the given rectangular prism? Which of these events are related through an omniscient narrator X=2 in standard form Olav receives psychotherapy as a result of his recently diagnosed disorder. Why is Olav most likely receiving this typeof treatment?He has anxiety about his disorder.He believes only in alternative treatments.He needs to manage extreme physical pain.He wants to avoid conventional medicine. Please answer this question now in two minutes railway cabooses just paid its annual dividend of 1.70 per share. The company has been reducing the dividends by 11.3 percent each year. How much are you willing to pay today to purchase stock in this company if your required rate of return is 12 percent? TWO MINUTES HELP MY PLEASE Which statement describe a pattern shown in the data? Which correctly lists the two elements that make up the empty space in the universe? *EN EL TEXTO* Es necesario que cada hombre establezca un pacto con el estado que lo comprometa a cumplir con las reglas que este seale , pues el ser humano es malo por naturaleza y sin autoridad fuerte que lo obliga actuar como se debe hara hasta los peores barbaridades 1.Cul es la tesis que propone el texto? 2.Que idea debilita la posicin del autor los hombres toman enserio los pactos que establecen individualmente con el estado a)Los seres humanos buscan gobiernos autoritarios que les den seguridad b)Los estados con slida autoridad no han podido detener las atrocidades que han podido llegar a ser el hombre c)La maldad en el ser humano siempre ha estado presente d)En los Estados con democracia de baja intensidad la gente se desborda 3.Qu sentido tiene la palabra pacto en el texto? Un jardinero cruz dos plantas de flores rosadas, con la esperanza de obtener plantas con flores del mismo color. Su sorpresa fue encontrar que, en la descendencia, aparecan flores rojas, rosadas y blancas en la proporcin 1:2:1. Pregunta: a) En qu se diferencia la herencia del color de estas flores y la de los guisantes? b) Indica el genotipo de las plantas del cruzamiento descrito. Which of the following is false? Correlation coefficient and the slope always have the same sign (positive or negative). If the correlation coefficient is 1, then the slope must be 1 as well. If the correlation between two variables is close to 0.01, then there is a very weak linear relation between them. Correlation measures the strength of linear association between two numerical variables. We have the following data for a hypothetical open economy: GNP = $12 comma 00012,000 Consumption (C) = $7 comma 2007,200 Investment (I) = $1 comma 0001,000 Government Purchases (G) = $1 comma 6001,600 Tax Collections (T) = $1 comma 2001,200 What is the value of private savings plus public savings? $nothing (Enter your answer as an integer. Include a minus sign if necessary.) What is the value of the current account balance CA? $nothing (Enter your answer as an integer. Include a minus sign if necessary.) simplify 3 x (x + 2) + 2 x ( 1 - x) Francisco states the following: When two or more factors are multiplied and they have the same sign, the product is positive. List two examples that support Francisco's statement. Show their products. Please help me with trig Id really appreciate how is DIO alive after he was stuck in Jonathons arms and how did he get into the secret compartment without erina knowing