x minute break in work rate problem

Question

Working alone at their respective constant rate, Audery can complete a certain job in 4 hours, while Ferris can do the same job in 3 hours. Audery and Ferris worked together on the job and completed it in 2 hours, but while Audery worked this entire time, Ferris worked for some of the time and took 3 breaks of equal length. How many minutes long was each of Ferris's breaks ?

I started with their combined work rate

$1/4 +1/3 = 7/12$

So they can SHOULD be done with the job in $12/7 = 1.71\,hours$

As they did it in 2 hours, Ferris's combined "Recess" time = $2-1.71 = .28 \,hour$

He did it 3 times, so each of them is $0.285/3=.095 \,hours \,, \,or \,5.71 \,minutes$

But answer is 10 minutes. What gives ?

Answer 1

In two hours nonstop, Audrey will complete half the job. That means Ferris did half a job too. At his rate, it takes 1.5 hours, leaving half an hour which he took off.

Divide this evenly by three, to obtain break lengths of ten (10) minutes.

Answer 2

When Audrey can complete a work in 4 hours, his rate of work is 1/4.When considered about Ferris, he can complete the work in 3 hours. In 1 hour, Audrey can do 1/4 of works.It means in 2hours he can do (1/4)*2 part of work. The remaining half part of work must be done by Ferris.Ferris can complete the remaining half work simultaneously in (3/2) hours.so he is left with 30 minutes. So he took 3equal breaks each of 10 minutes long