Question

If Jake does a job in 15 hours less time than Brianna, and they can do the job together in 10 hours, how long will it take each to do the job alone? It will take Jake ______ hours It will take Brianna _______ hours

Answer 1

It will take Jake 0 hours and It will take Brianna 15 hours

Explanation:

Let x be the no. of hours taken by Brianna to complete work alone

We are given that Jake does a job in 15 hours less time than Brianna

So,Jake work alone in hours =x-15

We are given that they can do the job together in 10 hours

So,
`(1)/(x-15)+(1)/(x)=(1)/(10)\\(x+x-15)/((x-15)x)=(1)/(10)\\x=3,15`

So, Brianna complete work in 15 hours

So, Jake work alone in hours =x-15=15-15=0

So, It will take Jake 0 hours and It will take Brianna 15 hours