15 scouts can sell all of their troop's cookies in 24 days. How many days would it take to sell the cookies if 18 scouts sell at the same rate?

Respuesta :

Answer:

29 days

Step-by-step explanation:

Given

15 scouts = 24 days

Required

Determine the number of days to sell 18 scouts

Represent the number of days for 18 scouts with x

i.e.

15 scouts = 24 days

18 scouts = x

Cross Multiply

15 scouts * x = 24 days * 18 scouts

15 * x = 24 days * 18

15x = 432 days

Divide through by 15

x = 432 /15 days

x = 28.8 days

Approximate

x = 29 days

Answer:

20 days

Step-by-step explanation:

So:

15 scouts=24 days

18 scouts=x days

15*1.2=18 (for the first equation of scouts to scouts)

Since this is a time problem, it should be inversely proportional- which also means that instead of multiplying for the second one as well, it should divide.

24/1.2=20

Let’s look at the ratio again:

15/24

18/20

In an inversely proportional answer, the product should be the same.

15*24=360

18*20=360

Therefore, the answer is correct.

[Also, if you were confused about the first answer, I think you got it wrong because you thought it was directly proportional, not inversely proportional. In time problems, it is inversely proportional because of the time span. Think of it: if 2 people eat 5 cookies in 2 minutes, then 4 people don’t eat 5 cookies in 4 minutes! Instead, the minutes shrinks because there are more people.]