Question

Jeffrey is using a copy machine to make posters for a school play. The machine prints the posters at a constant rate. After 3 minutes, he makes 108 posters. How long it will take Jeffrey to make 396 posters?

a.10 min B.11 min c.12 min d.9 min

Answer 1

B: 11 minutes.

Explanation:

So, we know that the machine prints at a constant rate.

After 3 minutes, the machine prints 108 posters.

So, let’s find the unit rate. We will divide the output over the input. So:

`108\text{ posters}/3\text{ minutes}=36\text{ posters/min}`

So, the unit rate of the machine is 36 posters per minute.

We can write an equation. If t represent the number of minutes and p represent the amount of posters, then:

`p=36t`

Gives the amount of posters p and t minutes.

We want to know how long it will take Jeffrey to make 396 posters.

So, we can substitute 396 for p and solve for t. Hence:

`396=36t`

Divide both sides by 36:

`t=11`

Therefore, it will take Jeffrey 11 minutes to make 396 posters.