Question

Molly and Liza are exercising. Molly does 12 push-ups at the same time as Liza does 15 push-ups.

When Molly does 40 push-ups, how many push-ups does Liza do?

Answer 1

Liza does 50 push-ups when Molly does 40 push-ups

Explanation:

`(12)/(15) =(40)/(x)` is the proportion we can use to find the amount of push-ups Liza does when Molly does 40

To solve for x, multiply 15 and 40 then divide the product by 12

15 × 40 = 600 ÷ 12 = 50

Answer 2

By the time that Molly does 40 push-ups,
Liza would have done 60.
This is solved simply by multiplying 15 by 4.
How did we get "15 × 4?"
Well, to get Molly's number of push-ups, we would have to see how many times Molly's original number, 10, could go into the end result, 40.
To get that, we would have to divide 40 into 10; which is 4.
So, we would multiply Liza's original number, 15, by 4.
Which would equal 60.

Hope this helps :)