What is g(x)?
5-
X
10
-10

Answer:

The answer is A) -9.7 > -18.2

Step-by-step explanation:

This is because, when you are thinking about negative numbers, the closer they are to 0, the greater they are. So, it is warmer in Minnesota.

Answer:

A and A

Step-by-step explanation:

Answer:

The formula is 1/2h(a+b)

h stands for the perpendicular height

a and b stand for the two horizontal lengths which are parallel to each other

Answer

option D

Step-by-step explanation:

The population of interest to the research is the set of all gun ownership status (yes/no) values for all adults in the country. Or all total adults in a country including those that own a gym or not. This is the population of interest. The sample is the 2550 individuals adults surveyed in the household telephone survey.

Step-by-step explanation:

can u give image PlZzzzz ....

Answer:

Hey!

Your answer should be Y=2x+4

Step-by-step explanation:

Hope this helps!

Answer:

a) The probability that a student will do homework regularly and also pass the course = P(H n P) = 0.57

b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P') = 0.12

c) The two events, pass the course and do homework regularly, aren't mutually exclusive. Check Explanation for reasons why.

d) The two events, pass the course and do homework regularly, aren't independent. Check Explanation for reasons why.

Step-by-step explanation:

Let the event that a student does homework regularly be H.

The event that a student passes the course be P.

- 60% of her students do homework regularly

P(H) = 60% = 0.60

- 95% of the students who do their homework regularly generally pass the course

P(P|H) = 95% = 0.95

- She also knows that 85% of her students pass the course.

P(P) = 85% = 0.85

a) The probability that a student will do homework regularly and also pass the course = P(H n P)

The conditional probability of A occurring given that B has occurred, P(A|B), is given as

P(A|B) = P(A n B) ÷ P(B)

And we can write that

P(A n B) = P(A|B) × P(B)

Hence,

P(H n P) = P(P n H) = P(P|H) × P(H) = 0.95 × 0.60 = 0.57

b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P')

From Sets Theory,

P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1

P(H n P) = 0.57 (from (a))

Note also that

P(H) = P(H n P') + P(H n P) (since the events P and P' are mutually exclusive)

0.60 = P(H n P') + 0.57

P(H n P') = 0.60 - 0.57

Also

P(P) = P(H' n P) + P(H n P) (since the events H and H' are mutually exclusive)

0.85 = P(H' n P) + 0.57

P(H' n P) = 0.85 - 0.57 = 0.28

So,

P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1

Becomes

0.03 + 0.28 + 0.57 + P(H' n P') = 1

P(H' n P') = 1 - 0.03 - 0.57 - 0.28 = 0.12

c) Are the events "pass the course" and "do homework regularly" mutually exclusive? Explain.

Two events are said to be mutually exclusive if the two events cannot take place at the same time. The mathematical statement used to confirm the mutual exclusivity of two events A and B is that if A and B are mutually exclusive,

P(A n B) = 0.

But, P(H n P) has been calculated to be 0.57, P(H n P) = 0.57 ≠ 0.

Hence, the two events aren't mutually exclusive.

d. Are the events "pass the course" and "do homework regularly" independent? Explain

Two events are said to be independent of the probabilty of one occurring dowant depend on the probability of the other one occurring. It sis proven mathematically that two events A and B are independent when

P(A|B) = P(A)

P(B|A) = P(B)

P(A n B) = P(A) × P(B)

To check if the events pass the course and do homework regularly are mutually exclusive now.

P(P|H) = 0.95

P(P) = 0.85

P(H|P) = P(P n H) ÷ P(P) = 0.57 ÷ 0.85 = 0.671

P(H) = 0.60

P(H n P) = P(P n H)

P(P|H) = 0.95 ≠ 0.85 = P(P)

P(H|P) = 0.671 ≠ 0.60 = P(H)

P(P)×P(H) = 0.85 × 0.60 = 0.51 ≠ 0.57 = P(P n H)

None of the conditions is satisfied, hence, we can conclude that the two events are not independent.

Hope this Helps!!!

Answer:

a) [tex]t = 1\,s[/tex], [tex]\dot A \approx 22619.467\,\frac{cm^{2}}{s}[/tex], b) [tex]t = 3\,s[/tex], [tex]\dot A \approx 67858.401\,\frac{cm^{2}}{s}[/tex], c) [tex]t = 5\,s[/tex], [tex]\dot A \approx 113097.336\,\frac{cm^{2}}{s}[/tex]. The rate at which the area within the circle is increasing linearly inasmuch as time passes by.

Step-by-step explanation:

The area of a circle is described by the following formula:

[tex]A = \pi \cdot r^{2}[/tex]

Where:

[tex]A[/tex] - Area, measured in square centimeters.

[tex]r[/tex] - Radius, measured in centimeters.

Since circular ripple is travelling outward at constant speed, radius can be described by the following equation of motion:

[tex]r (t) = \dot r \cdot t[/tex]

Where:

[tex]\dot r[/tex] - Speed of the circular ripple, measured in centimeters per second.

[tex]t[/tex] - Time, measured in seconds.

The rate of change of the circle is determined by deriving the equation of area and replacing radius with the function in terms of the speed of the circular ripple and time. That is to say:

[tex]\dot A = 2\cdot \pi \cdot r \cdot \dot r[/tex]

[tex]\dot A = 2 \cdot \pi \cdot \dot r^{2}\cdot t[/tex]

Where:

[tex]\dot A[/tex] - Rate of change of the circular area, measured in square centimeters per second.

[tex]\dot r[/tex] - Speed of the circular ripple, measured in centimeters per second.

[tex]t[/tex] - Time, measured in seconds.

If [tex]\dot r = 60\,\frac{cm}{s}[/tex], then:

a) [tex]t = 1\,s[/tex]

[tex]\dot A = 2\cdot \pi \cdot \left(60\,\frac{cm}{s} \right)^{2}\cdot (1\,s)[/tex]

[tex]\dot A \approx 22619.467\,\frac{cm^{2}}{s}[/tex]

b) [tex]t = 3\,s[/tex]

[tex]\dot A = 2\cdot \pi \cdot \left(60\,\frac{cm}{s} \right)^{2}\cdot (3\,s)[/tex]

[tex]\dot A \approx 67858.401\,\frac{cm^{2}}{s}[/tex]

c) [tex]t = 5\,s[/tex]

[tex]\dot A = 2\cdot \pi \cdot \left(60\,\frac{cm}{s} \right)^{2}\cdot (5\,s)[/tex]

[tex]\dot A \approx 113097.336\,\frac{cm^{2}}{s}[/tex]

The rate at which the area within the circle is increasing linearly inasmuch as time passes by.

Answer:

The probability that at exactly one of them does exactly two language classes is 0.32.

Step-by-step explanation:

We can model this variable as a binomial random variable with sample size n=2.

The probability of success, meaning the probability that a student is in exactly two language classes can be calculated as the division between the number of students that are taking exactly two classes and the total number of students.

The number of students that are taking exactly two classes is equal to the sum of the number of students that are taking two classes, minus the number of students that are taking the three classes:

[tex]N_2=F\&S+S\&G+F\&G-F\&S\&G=12+4+6-2=20[/tex]

Then, the probabilty of success p is:

[tex]p=20/100=0.2[/tex]

The probability that k students are in exactly two classes can be calcualted as:

[tex]P(x=k) = \dbinom{n}{k} p^{k}(1-p)^{n-k}\\\\\\P(x=k) = \dbinom{2}{k} 0.2^{k} 0.8^{2-k}\\\\\\[/tex]

Then, the probability that at exactly one of them does exactly two language classes is:

[tex]P(x=1) = \dbinom{2}{1} p^{1}(1-p)^{1}=2*0.2*0.8=0.32\\\\\\[/tex]

Answer:

see below

Step-by-step explanation:

You can remove one or more of the other color marbles to increase the probability of drawing a green marble

or

You can add  one or more green marbles to have more green marbles in the bag

Step-by-step explanation:

y=7x-10

Answer:

[tex]\huge \boxed{y=7x-10}[/tex]

Step-by-step explanation:

[tex]-7x+y=-10[/tex]

[tex]\sf Add \ 7x \ on \ both \ sides.[/tex]

[tex]-7x+y+7x=-10+7x[/tex]

[tex]y=7x-10[/tex]

Answer:

Considering the audience helps a writer identify the types of details and language needed in the writing. Considering the audience helps the writer identify what is important to him or her. Considering the audience allows the writer to write about what he or she wants. Knowing the audience for a particular essay is important because it determines the content that will appear in the writing. If you are arguing for a change to occur, identifying the level at which you want this change to occur and/or the people you want to persuade to help create this change (audience) is important step by step

Answer:

9672 per year

Step-by-step explanation:

Take the amount he earns per week times the number of weeks he works

186* 52

9672 per year

Answer:

$9672

Step-by-step explanation:

Jack earns $186 in 1 week.

In 52 weeks,

186 × 52 = 9672

He earns $9672.

Answer:

x= -3 +√2 ≈ -0.1716,  and x = - 3 -2√2 ≈ -5.8284

Step-by-step explanation:

y= -1/2(x+3)² +4

For x -intercept, y = 0.

0 = - 1/2(x+3)² + 4 /*(-2)

0 = (x+3)² - 8

(x+3)² = 8

√(x+3)² = +/-√8

x+3 = +/-√8

x = - 3+/- 2√2

x= -3 +√2 ≈ -0.1716,  and x = - 3-2√2 ≈ -5.8284

Answer:

a. 0.4772 = 47.72 %

b. 0.7605 = 76.05 %

Step-by-step explanation:

What we must do is calculate the z value for each value and thus find what percentage each represents and the subtraction would be the percentage between those two values.

We have that z is equal to:

z = (x - m) / (sd)

x is the value to evaluate, m the mean, sd the standard deviation

a. ind the least proportion of data falls between 70 and 80 If the histogram is bell shaped:

So for 70 copies we have:

z = (70 - 70) / (5)

z = 0

and this value represents 0.5

So for 80 copies we have:

z = (80 - 70) / (5)

z = 2

and this value represents 0.9772

p (70 > x > 80) = 0.9772 - 0.5

p (70 > x > 80) = 0.4772 = 47.72 %

b.  Find the proportion of data between 65 and 77

So for 65 copies we have:

z = (65 - 70) / (5)

z = -1

and this value represents 0.1587

So for 77 copies we have:

z = (77 - 70) / (5)

z = 1.4

and this value represents 0.9192

p (65 > x > 77) = 0.9192 - 0.1587

p (65 > x > 77)  = 0.7605 = 76.05 %

Answer:

a. p=0.562

b. E = 0.0253

c. The 90% confidence interval for the population proportion is (0.537, 0.587).

d. We have 90% confidence that the interval (0.537, 0.587) contains the true value of the population proportion.

Step-by-step explanation:

We have to calculate a 90% confidence interval for the proportion.

The sample proportion is p=0.562.

[tex]p=X/n=583/1038=0.562[/tex]

The standard error of the proportion is:

[tex]\sigma_p=\sqrt{\dfrac{p(1-p)}{n}}=\sqrt{\dfrac{0.562*0.438}{1038}}\\\\\\ \sigma_p=\sqrt{0.000237}=0.0154[/tex]

The critical z-value for a 90% confidence interval is z=1.645.

The margin of error (MOE) can be calculated as:

[tex]MOE=z\cdot \sigma_p=1.645 \cdot 0.0154=0.0253[/tex]

Then, the lower and upper bounds of the confidence interval are:

[tex]LL=p-z \cdot \sigma_p = 0.562-0.0253=0.537\\\\UL=p+z \cdot \sigma_p = 0.562+0.0253=0.587[/tex]

The 90% confidence interval for the population proportion is (0.537, 0.587).

We have 90% confidence that the interval contains the true value of the population proportion.

Answer:

a) The volume of the wooden block is 240 cm^3.

b) The density of the wooden block is 0.7 g/cm^3.

Step-by-step explanation:

The volume of the rectangular wooden block can be calculated as the multiplication of the length in each dimension: length, wide and height.

With dimensions 10 cm x 3 cm x 8 cm, the volume is:

[tex]V=L\cdot W\cdot H = 10\cdot 3\cdot 8=240[/tex]

The volume of the wooden block is 240 cm^3.

If we know that the mass of the wooden block is 168 g, we can calculate the density as:

[tex]\rho = \dfrac{M}{V}=\dfrac{168}{240}=0.7[/tex]

The density of the wooden block is 0.7 g/cm^3.

Answer:x>-1

Step-by-step explanation:

Step 1: Subtract 3 from both sides.

-3x+3-3<6-3

-3x<3

Step 2: Divide both sides by -3.

-3x/-3<3/3

X>-1

Answer:

  56.25°

Step-by-step explanation:

The definition of the cosine function tells you that

  cos(B) = BC/BA

  B = arccos(BC/BA) = arccos(5/9)

  B ≈ 56.25°

Answer:

The length of the short side is 14.5 units, the length of the other short side is 18.5 units, and the length of the longest side is 23.5 units.

Step-by-step explanation:

The Pythagorean Theorem

If a and b are the lengths of the legs of a right triangle and c is the length of the hypotenuse, then the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse.

This relationship is represented by the formula:

                                                     [tex]a^2+b^2=c^2[/tex]

Applying the Pythagorean Theorem  to find the lengths of the three sides we get:

[tex](x)^2+(x+4)^2=(x+9)^2\\\\2x^2+8x+16=x^2+18x+81\\\\2x^2+8x-65=x^2+18x\\\\2x^2-10x-65=x^2\\\\x^2-10x-65=0[/tex]

Solve with the quadratic formula

[tex]\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}[/tex]

[tex]x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]

[tex]\mathrm{For\:}\quad a=1,\:b=-10,\:c=-65:\quad x_{1,\:2}=\frac{-\left(-10\right)\pm \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}\\\\x_{1}=\frac{-\left(-10\right)+ \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5+3\sqrt{10}\\\\x_{2}=\frac{-\left(-10\right)- \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5-3\sqrt{10}[/tex]

Because a length can only be positive, the only solution is

[tex]x=5+3\sqrt{10}\approx 14.5[/tex]

The length of the short side is 14.5, the length of the other short side is [tex]14.5+4=18.5[/tex], and the length of the longest side is [tex]14.5+9=23.5[/tex].

Answer:

t = 0

Before it starts rushing that's when it will be fastest

Step-by-step explanation:

For the water ib the tank to flow very fast it means that there is a big volume of water present.

And for volume of water to be present that much it means that the water must

have not leaked much or at all.

And for that it signifies large volume of water.

If we do the calculation we'd see that time will be actually equal to zero for the pressure and the volume of the water to be biggest.

V = 4500 (1 − 1 /50 t )^2

V = 4500

4500 = 4500(1- 1/50t)²

1 = 1- 1/50t

0 = -1/50t

t = 0

Answer:

Step-by-step explanation:

The question is incomplete and lacks the required diagram. Find the diagram attached. Here is also the complete question.

"The formula for the area of a parallelogram is A = bh, where b is the base and h is the height. Which simplified expression represents the area of the parallelogram? –4x3 + 14x – 24 square centimeters 2x3 – 6x2 – 14x + 24 square centimeters –4x3 – 14x + 24 square centimeters 2x3 + 6x2 + 14x + 24 square centimeters"

Area of a parallelogram = Base * Height.

Given the height of the parallelogram = (x-4)cm

Base = (2x² + 2x-6) cm

Area of the parallelogram =  (x-4)cm *  (2x² + 2x-6) cm

Area of the parallelogram = (x-4)(2x²+2x-6)

Area of the parallelogram = 2x³+2x²-6x-8x²-8x+24

= 2x³+2x²-8x²-6x-8x+24

=  (2x³-6x²-14x+24)cm²

The missing part in the question;

and the payoff is $2.20 won for every dollar bet. (As the player’s probability of winning in this case is [tex]\dfrac{1}{4}[/tex]........

Also:

For such a bet, the casino pays off as shown in the following table.

The table can be shown as:

Keno Payoffs in 10 Number bets

Number of matches        Dollars won for each $1 bet

0  -   4                                        -1

5                                                  1

6                                                  17

7                                                  179

8                                                 1299

9                                                 2599

10                                               24999

Answer:

Step-by-step explanation:

Given that:

Twenty numbers are selected at random by the casino from the set of numbers 1 through 80

A player can select from 1 to 15 numbers; a win occurs if some fraction of the player’s chosen subset matches any of the 20 numbers drawn by the house

Let assume X to represent the numbers of player chooses which are in the Casino-selected-set of 20.

Let assume the random variable X has a hypergeometric distribution with parameters  N= 80 and m =20.

Then, the probability mass function of a hypergeometric distribution can be defined as:

[tex]P(X=k)=\dfrac{(^m_k)(^{N-m}_{n-k})}{(^N_n)}, k =1,2,3 ... n[/tex]

Now; the probability that i out of  n numbers chosen by the player among 20  can be expressed as:

[tex]P(X=k)=\dfrac{(^{20}_k)(^{60}_{n-k})}{(^{80}_n)}, k =1,2,3 ... n[/tex]

Also; given that ; When the player selects 2 numbers, a payoff (of odds) of $12 won for every $1 bet is made when both numbers are among the 20

So; n= 2; k= 2

Then :

Probability P ( Both number in the set 20)  [tex]=\dfrac{(^{20}_2)(^{60}_{2-2})}{(^{80}_2)}[/tex]

Probability P ( Both number in the set 20) [tex]= \dfrac{20*19}{80*79}[/tex]

Probability P ( Both number in the set 20) [tex]=\dfrac{19}{316}[/tex]

Probability P ( Both number in the set 20) [tex]=\dfrac{1}{16.63}[/tex]

Thus; the payoff odd for [tex]=\dfrac{1}{16.63}[/tex] is 16.63:1 ,as such fair payoff in this case is $16.63

Again;

Let assume X to represent the numbers of player chooses which are in the Casino-selected-set of 20.

Let assume the random variable X has a hypergeometric distribution with parameters  N= 80 and m =20.

The probability mass function of the hypergeometric distribution can be defined as :

[tex]P(X=k)=\dfrac{(^m_k)(^{N-m}_{n-k})}{(^N_n)}, k =1,2,3 ... n[/tex]

Now; the probability that i out of  n numbers chosen by the player among 20  can be expressed as:

[tex]P(n,k)=\dfrac{(^{20}_k)(^{60}_{n-k})}{(^{80}_n)}, k =1,2,3 ... n[/tex]

From the table able ; the expected payoff can be computed as shown in the attached diagram below. Thanks.

Answer: 41 candles

Step-by-step explanation:

Multiply the dimensions of the candle first.

V = l*w*h

7 * 2 = 14

14 * 10 = 140

Now, divide the total amount of wax used by the amount of wax used for one candle.

5,740 / 140 = 41

Answer:

(a) The standard error of the mean is 0.091.

(b) The probability that the sample mean will be less than $7.75 is 0.0107.

(c) The probability that the sample mean will be less than $8.10 is 0.9369.

(d) The probability that the sample mean will be more than $8.20 is 0.0043.

Step-by-step explanation:

We are given that the average price for a movie in the United States in 2012 was $7.96.

Assume the population standard deviation is $0.50 and that a sample of 30 theaters was randomly selected.

Let [tex]\bar X[/tex] = sample mean price for a movie in the United States

The z-score probability distribution for the sample mean is given by;

                              Z  =  [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]  ~ N(0,1)

where,  [tex]\mu[/tex] = population mean price for a movie = $7.96

            [tex]\sigma[/tex] = population standard deviation = $0.50

            n = sample of theaters = 30

(a) The standard error of the mean is given by;

     Standard error  =  [tex]\frac{\sigma}{\sqrt{n} }[/tex]  =  [tex]\frac{0.50}{\sqrt{30} }[/tex]

                                =  0.091

(b) The probability that the sample mean will be less than $7.75 is given by = P([tex]\bar X[/tex] < $7.75)

  P([tex]\bar X[/tex] < $7.75) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{7.75-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < -2.30) = 1 - P(Z [tex]\leq[/tex] 2.30)

                                                         = 1 - 0.9893 = 0.0107

The above probability is calculated by looking at the value of x = 2.30 in the z table which has an area of 0.9893.

(c) The probability that the sample mean will be less than $8.10 is given by = P([tex]\bar X[/tex] < $8.10)

  P([tex]\bar X[/tex] < $8.10) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{8.10-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < 1.53) = 0.9369

The above probability is calculated by looking at the value of x = 1.53 in the z table which has an area of 0.9369.

(d) The probability that the sample mean will be more than $8.20 is given by = P([tex]\bar X[/tex] > $8.20)

  P([tex]\bar X[/tex] > $8.20) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] > [tex]\frac{8.20-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z > 2.63) = 1 - P(Z [tex]\leq[/tex] 2.63)

                                                         = 1 - 0.9957 = 0.0043

The above probability is calculated by looking at the value of x = 2.63 in the z table which has an area of 0.9957.

Answer:

[tex]\boxed{\df\ \dfrac{-19}{2}}[/tex]

Step-by-step explanation:

Hi,

x=-2

it gives

9*(-2)-4y=20

<=> -18-4y=20

<=> 18-18-4y=20+18=38

<=> -4y=38

<=> y = -38/4=-19/2

hope this helps

Answer:

-45/2 - 12/2 = -57/2

Step-by-step explanation:

Substitute 15 for x in the given equation:  y = (-3/2)x - 6 becomes

y = (-3/2)(15) - 6 = -45/2  -  6 when x = 15.  This is equivalent to -57/2

Answer:

a = T - 4

Step-by-step explanation:

Simply just subtract 4 on both sides to get the answer!

Answer:

a=T-4

Step-by-step explanation:

subtract 4

Step-by-step explanation:

solve f(x) by supposing it has y and and then interchange it with x .

hope this is helpful

Answer:

See the answers below.

Step-by-step explanation:

[tex]a.\:\frac{f\left(x\right)-f\left(a\right)}{x-a}=\frac{2x^2-x-5-\left(2a^2-a-5\right)}{x-a}\\\\=\frac{2x^2-x+a-2a^2}{x-a}\\\\=\frac{2\left(x+a\right)\left(x-a\right)-1\left(x-a\right)}{x-a}\\\\=\frac{\left(x-a\right)\left[2\left(x+a\right)-1\right]}{x-a}\\\\=2x+2a-1\\\\\\b.\:\frac{f\left(x+h\right)-f\left(x\right)}{h}=\frac{2\left(x+h\right)^2-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\\\=\frac{2\left(x^2+2xh+h^2\right)-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\[/tex]

Expand and simplify to get:

[tex]=\frac{2h^2+4xh-h}{h}\\\\=\frac{h\left(2h+4x-1\right)}{h}\\\\=2h+4x-1[/tex]

Best Regards!

Answer:

Option B

Step-by-step explanation:

The number that had never been married will vary in each sample due to the random selection of adults.

This number will vary in each sample to the random selection process but they might or might not be as close as possible to one another after sampling.

Answer:

The food would last 51 days

Step-by-step explanation:

After 15 days are over, you could say that the 16th day would be as follows -

80 soldiers, food finished in 60 - 15 = 45 days.

If 20 more soldiers arrive, there would be a total of 100 soldiers, so if  80 soldiers can finish their food in 45 days  - 1 soldier can finish = 45 * 80. Respectively,  100 soldiers can consume their food in ( 45 * 80 ) / 100  = 36 days.

As 15 days are already over, adding 36 more days = 51 days

The food would last 51 days if 20 more soldiers join after 15 days

There are several possible ways to answer this question, but I hope that explanation helps!

Answer:

A total of 51 days, or 36 days after the extra soldiers join in.

Step-by-step explanation:

Let's say a soldier eats 1 portion of food in 1 days. That portion may be divided into breakfast, lunch , and dinner, but it is still accounted as 1 portion per soldier per day.

There are 80 soldiers and enough food for 60 days.

The number of portions is

60 * 80 = 4800

The fort started with 4800 portions.

80 soldiers ate their portions for 15 days.

80 * 15 = 1200

After 15 days, they have

4800 - 1200 = 3600 portions left.

After 15 days, 20 more soldiers joined in.

Now there are 80 + 20 = 100 soldiers.

There are 3600 portions left for 100 soldiers.

3600/100 = 36

The food would last 36 days after the 15 days, or a total of 51 days.