Four years ago the average age of A,B and C was 25 years. Five years ago the average age of B and C was 20 years. A's present age is ​

Answers

Answer 1
Given:

Four years ago average age of A , B & C was 25 years.

Find:

A's present age

Solution:

Let the ages of A , B , C be A , B , C years.

Age of A before 4 years = (A - 4) years. Age of B before 4 years = (B - 4) years. Age of C before 4 years = (C - 4) years.

We know that,

Average = Sum of observations/Number of observations.

Here,

Sum of observations = A - 4 + B - 4 + C - 4 = (A + B + C - 12) years.

Number of observations = 3.

So, (A + B + C - 12)/3 = 25

⟹ A + B + C - 12 = 3 * 25

⟹ A + B + C = 75 + 12

⟹ A + B + C = 87 -- equation (1)

Also given that,

Average age of B & C before 5 years was 20 years.

⟹ (B - 5 + C - 5)/2 = 20

⟹ B + C - 10 = 2 * 20

⟹ B + C = 40 + 10

⟹ B + C = 50 -- equation (2)

Subtract equation (2) from equation (1).

⟹ A + B + C - (B + C) = 87 - 50

⟹ A + B + C - B - C = 37

⟹ A = 37 years

∴ A's present age is 37 years.

I hope it will help you.

Regards.

Answer 2

Answer:

→ md - 2nd + 3md = 2 * [ a + (n - 1)d ]

→ 4md - 2nd = 2 * [ a + (n - 1)d ]

→ 2(2md - nd) = 2 * (a + nd - d)

→ 2md - nd - a + d = nd

→ 2md - nd - (md - 2nd) + d = nd

[ From equation (1) ]

→ 2md - nd - md + 2nd + d = nd

→ md + nd + d = nd

→ (m + n + 1)d = n * d

→ (m + n + 1) = n

Step-by-step explanation:


Related Questions

If side a = 3 and b = 4 what is the length of leg c in a right triangle using the
pythagorean theorem?

Answers

Answer: 5

Step-by-step explanation: Leg A + Leg B= Leg C

9+16=25 the square of 25 is 5

Answer:

5 = c

Step-by-step explanation:

pythagorean theorem is simply a^2 + b^2 = c^2

so a=3 and b=4 so we plug them in

3^2 + 4^2 = c^2

which is

9 + 16 = c^2

so

25 = c^2

then we take the square root for the answer!!

sqrt(25) = sqrt(c^2)

5 = c

Please just do whatever you can

Answers

Answer:

6. -62/289 or -0.249135

Explanation:

8/17x-3/5=-24/85x15/17= -62/289

Apply a 90 degree rotation to the point (1, 2)

Answers

Answer:

(-1,2)

Step-by-step explanation:

90 degree rotation from (a,b) is (-a,b)

3/4 change 3/4 to a decimal show work

Answers

Answer:

0.75

Step-by-step explanation:

You just need to convert 3/4 into a decimal.

For example: If you get 3 out of 4 problems right on a quiz, in percent form it will be a 75%, in decimal form 0.75 because you'll move the percent sign 2 spaces to the left. That will then be a decimal if you're converting 75% to 0.75.

3 divided by 4 is also going to give you 0.75. Because, a "fraction slash" is the dividing point. So,

3/4 = 0.75

12 ft
8 ft
8 ft
Find the area of the kite.

Answers

Answer:

The area of the kite would be 48.

48 is the area of the kite

22+54=y+16 whats the answer

Answers

Answer:

y=60 or 60=y

Step-by-step explanation:

22+54= 76

76=y+16

60=y or the other way around

3x-100 what does x equal?

Answers

Yes it’s 33.33 repeating

Ethan builds two different kinds of chairs, rockers and swivels. It takes him 3 hours to build a rocker and requires 2 oz of stain. It takes him 2 hours to build a swivel chair and requires 8 oz of stain. Ethan has 56 oz of stain available and he can only work up to 24 hours. He makes $12 profit on each rocker and $10 profit on each swivel chair. 1. Since there cannot be negative chairs, create two constraints to represent this. 2.Create a constraint for the hours it takes to build the chairs. 3. Create a constraint for the stain it takes for the chairs. PLEASE HELP

Answers

Answer:

(1) [tex]x\geq 0\; \text {and}\;y\geq 0[/tex]

(2) [tex]3x + 2y\leq[/tex] 24

(3) [tex]x+4y\leq 28[/tex]

Step-by-step explanation:

Let x and y be the numbers of rockers and swivels made by Ethan.

(1) Since the number of chairs can't be negative. So,

x\geq0 and y\geq 0 are the two constraints.

(2) He can work a maximum of 24 hours.

The time required to make 1 rocker chair and 1 swivels chair are 3 hr and 2 hr respectively.

So, the time required to make x rocker chair = 3x hr

and the time required to make y swivel chair = 2y hr.

The total time required is  3x + 2y hr which can't be more than the available time, 24 hr.

So, the required constraint is

[tex]3x + 2y\leq 24[/tex]

(3) Similarly,

As 1 rocker chair requires 2 oz strain and 1 swivel chair required 8 ox strain.

So, to make x rocker chair 2x oz required and make y swivel chair 8y oz required which can't be more than the available oz, 56.

So, the required constraint is

[tex]2x + 8y\leq 56[/tex]

[tex]\Rightarrow x+4y\leq 28.[/tex]

The number of animals at the is shown in the table. Write a ratio to represent giraffes to otters.

Answers

Answer:

The ratio of giraffes to otters is 8:16. If simplified it's 1:2

Step-by-step explanation:

find the cube of 2.9​

Answers

Step-by-step explanation:

[tex] {2.9}^{3} \\ 2.9 \times 2.9 \times 2.9 \\ 8.41 \times 2.9 \\ 24.389[/tex]

Answer:

The cube of [tex]2.9[/tex] is [tex]24.389[/tex].

Which choice best represents the sum of (5 + 8x - 3) and (9x - 6)
17x +-4
17x + 4
x + 14
x+ - 14

Answers

Answer:

17x−4

Step-by-step explanation:

Let's simplify step-by-step.

5+8x−3+9x−6

=5+8x+−3+9x+−6

Combine Like Terms:

=5+8x+−3+9x+−6

=(8x+9x)+(5+−3+−6)

=17x+−4

If anyone answers, I love you.

Answers

Answer:

-5 7

6 -3

-9 1

Step-by-step explanation:

im so sorry if im wrong don't sew meh

What’s the highest common multiple?

Answers

Answer:

HCF = 90

Step-by-Step explanation:

2 × 3⁴× 5 = 810

2³× 3²× 5²= 1800

Find the prime factorization of 810

810 = 2 × 3 × 3 × 3 × 3 × 5

Find the prime factorization of 1800

1800 = 2 × 2 × 2 × 3 × 3 × 5 × 5

To find the HCF, multiply all the prime factors common to both numbers:

Therefore, HCF = 2 × 3 × 3 × 5

HCF = 90

Solve: 3(g − 2) = 8

Answers

Answer:

g=4⅔

Step-by-step explanation:

3(g - 2)=8

3g -6 = 8

3g= 8+6

3g= 14

[tex] \frac{3g}{3} = \frac{14}{3} [/tex]

g=4⅔

hope this helps

Step-by-step explanation:

3(g - 2) = 8

3(g - 2) = 8

+ 2 +2

3g = 8

3÷3= 0 8÷3 = 4.6

so your answer will be g= 4.6 (5 if you round it up) or if you need it in fraction form it will be 4 and 2/3

Enter the correct answer in the box by replacing the values of m and b.

Answers

Answer:

f(x) = -2x + 5  Plato

Step-by-step explanation:

The double number line shows the approximate number of ounces in a certain number of pounds:

Based on the number line, about how many ounces are there in 10 pounds?
Group of answer choices
144 ounces
160 ounces
176 ounces
192 ounces

Answers

Answer:

B- 160

Step-by-Step Explanation:

I did it before and I was rite, so trust me

Answer:

B 160

Step-by-step explanation:

help me pleaseeeeeeeeeeeeeeeeeeeeeee

Answers

A they’re parallel because they have same slope

PLEASE HELP ME! I am not sure how to answer this question.​

Answers

Answer:

yes

Step-by-step explanation:

the diagnols are congruent meaning that the diagnol lines in the middle are the same length. So theoretically the left and right lengths are the same, and the top and bottom lengths are the same. The triagles named both have the same base and they're hieght is sbviouysly the same so they would be SSS each of the sides on one triangle coresspondes to the other.

Suppose there is a 1.7f drop in temperature for every thousand feet that an airplane climbs into the sky. If the temperature on the ground is 49.9f what will be the temperature when the plane reaches am altitude of 4,000ft?? The temperature will be_____F (type an integer or a decimal)

Answers

Answer:

[tex]43.1 ^{\circ}F[/tex]

Step-by-step explanation:

Give that for every 1000 feet increase in the height there is a drop of [tex]1.7 ^{\circ}F[/tex] in temperature.

So, the rate of temperature drop with respect to height, R = 1.7/1000 [tex]^{\circ}F/\text{ft}[/tex].

If the change in height is [tex]\Deltah[/tex][tex]\Delta h[/tex] feet, the temperature drop,

[tex]\Delta T= \Delta h R \;^{\circ}F\cdots(i)[/tex]

The temperature on the ground is 49.9 [tex]^{\circ}F[/tex].

At the ground, the height is 0, so the change in height, \Delta h when the plane reaches an altitude of 4,000 feet, is

\Delta h =4000-0=4000 feet

Now, from equation (i), the temperature drop

[tex]\Delta T= 4000 \times \frac {1.7}{1000}=6.8\;^{\circ}F.[/tex]

Hence, the temperature at an altitude of 4000 feet [tex]= 49.9-6.8=43.1 \;^{\circ}F[/tex].

2) If 20 workers can build a house in 45 days, how many more workers are needed
to complete it in 30 days?
А
6
B
15
С
10
D
18

Answers

It’s D 18 if wrong I’m sorry but I took this test as well

Answer:

B

Step-by-step explanation:

HELP!! please explain how you got the answer too.

Determine whether cach point lies on the graph of the line y = 4.6x -7.

H(0, -7) ​

Answers

Answer:

Point H does lie on the graph y = 4.6x - 7

Step-by-step explanation:

Step 1: Define

y = 4.6x - 7

H(0, -7)

Step 2: Substitute, Evaluate, and Check

-7 = 4.6(0) - 7

-7 = 0 - 7

-7 = -7

Answer:

H(0,-7) does lie on the graph of line y = 4.6x - 7

Step-by-step explanation:

All you have to do is simply plug in the x and y values.

From the point H (0,-7) we can say that

x = 0

y = -7

Now just plug it into the equation.

y = 4.6x - 7

(-7) = 4.6(0) - 7

-7 = -7

Since -7 does equal -7, the point H is on the line of y = 4.6x - 7.

Which expression is equal to 527.471?*
(5x100)+(2x10)+(7x1)+(4x10) + (7x100)+ (1x1,000)
(5x100,000)+(2x10,000)+(7x1,000)+(4x100) + (7x10)+ (1x1)
(5x100)+(2x10)+(7x1)+(4x1/1) + (7x1/10)+ (1x1/100)
(5x100)+(2x10)+(7x1)+(4x1/10) + (7x1/100)+ (1x1/1,000)

Answers

Answer:

Step-by-step explanation:

527.471 =(5 ×100.000) +(2 ×10.000) +(7 ×1.000) +(4 ×100) +(7 ×10) +(1×1)

Answer:

500029301.171

Step-by-step explanation:

which algebraic expression represents the phrase "the quotient of negative eight and the sum of a number and three"

Answers

Answer:

Let x be that number.

[tex] - 8 \div (x + 3)[/tex]

The quotient is the result of dividing a number by another. In this case, the numbers are - 8 and x + 3.

What’s the correct mathematical expression for 2 groups of z

Answers

Answer:

2z = 2 groups of z

What is the solution to the linear equation?

–12 + 3b – 1 = –5 – b

b = –2
b = –1.5
b = 1.5
b = 2

Answers

Step-by-step explanation:

If you have any questions about the way I solved it, don't hesitate to ask me in the comments below ;)

The solution to the linear equation –12 + 3b – 1 = –5 – b is:

b = 2

The linear equation is:

–12 + 3b – 1 = –5 – b

Collect like terms

-12  -  1 + 5  =  -b  -  3b

Simplify the rearranged equation

-8   =   -4b

Divide both sides by -4

[tex]\frac{-8}{-4} = \frac{-4b}{-4}[/tex]

The given expression, after dividing both sides by -4, will give:

2  =  b

Rewriting the resulting solution:

b  =  2

Therefore, the solution to the linear equation –12 + 3b – 1 = –5 – b is:

b = 2

Learn more here: https://brainly.com/question/2159099

please help. i will mark brainleast

Answers

the answer is 9. hope this helps

Answer:

9 is the answer.

Both negative signs cancel eachother, so you just have 45/5.

Step-by-step explanation:

Good luck! <3

A 5000 seat theater has tickets for sale at 26 and 40. How many tickets should be sold at each price for a sellout performance to generate a total revenue of 153800.

Answers

Answer:

The number of tickets for sale at $26 should be 3300

The number of tickets for sale at $40 should be 1700

Step-by-step explanation:

Use 2 equations to represent the modifiers within the problem:

[tex]5000 = a + b \\ 153800 = 26a + 40b[/tex]

Now you want to find the point at which the variables are changed to make both equations correct, this can be done by graphing and finding the intersection of both lines.

[tex]5000 = 3300 + 1700 \\ 153800 = 26(3300) + 40(1700)[/tex]

Multiply. −2⋅(4)⋅(−3)⋅(5) −120 −4 4 120

Answers

Answer:

-44120

Step-by-step explanation:

How are lines KL and MN related?
O The lines intersect at point K.
O The lines are parallel.
O The lines are perpendicular.
O The lines do not have slopes,

Answers

The lines are perpendicular

The lines KL and MN perpendicular to each other.

What is slope?

In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line. The slope of a line is a measure of its steepness. Mathematically, slope is calculated as "rise over run" (change in y divided by change in x).

here, we have,

If a line passes through two points, then the slope of the line is

m = y2-y1/x2-x1

From the given graph it is clear that coordinates of points on line KL are K(-8,2) and L(6,2).

The slope of line KL is

m = 0

The slope of line KL is 0, it means it is a horizontal line.

From the given graph it is clear that coordinates of points on line MN are M(-4,8) and N(-4,-6).

The slope of line MN is

m = 1/0

The slope of line MN is 1/0 or undefined, it means it is a vertical line.

We know that vertical and horizontal lines are perpendicular to each other.

Therefore the lines KL and MN perpendicular to each other.

To learn more on slope click:

brainly.com/question/3605446

#SPJ7

¡¡ANSWER MY QUESTION FIRST¡¡

Can you help me with these questions, please?

Answers

Answer:

∠5 = 70°

∠8 = 130°

Step-by-step explanation:

Since ∠5 and ∠1 are equal they will both equal 70°

Since ∠6 and ∠8 are also equal they will both equal 130°

Hope this helps

Plz mark brainliest

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