Question 597852
Let they both complete the job in X hrs
Jeremy can do the work twice as fast as Brook,
So time taken by Jeremy will be HALF than that of Brook
Time taken by Brook = 4hrs
So Work rate of Brook = 1/4

Time taken by Jeremy = 2 hrs
So Work rate of Jeremy = 1/2

{{{1/4+1/2=1/X}}}
{{{3/4=1/X}}}

So X = 4/3 Hrs,i.e. 1 Hour & 20 Minutes

So when the work together, they complete the job in 1 Hour & 20 Minutes