Question

Mailyn loves cookies. She can eat 32 in an hour. Her brother Juan, however, needs 3 hours to eat the same amount of cookies. How long will it take them to eat 40 cookies together?

Answer 1

we know that

1) Mailyn can eat 32 cookies in an hour

1 hour is equal to 60 minutes

Find how cookies eats Mailyn in one minute

by proportion

`(32)/(60) (cookies)/(minutes)= (x)/(1) (cookie)/(minutes) \\\\ x=32/60\\x=0.53 \ cookies`

2) Juan needs 3 hours to eat 32 cookies

Find how cookies eats Juan in one minute

by proportion

`(32)/(180) (cookies)/(minutes)= (x)/(1) (cookie)/(minutes) \\\\x=32/180 \\x=0.18\ cookies`

3) Find how long will it take them to eat 40 cookies together

we know that

Maylin and Juan eats in one minute together ---------> (0.53+0.18)=0.71 cookies

so

by proportion

`(0.71)/(1) (cookies)/(minutes)= (40)/(x) (cookie)/(minutes) \\\\0.71*x=40\\x=56.34 \ minutes`

therefore

the answer is

`56.34\ minutes`