Question

X can do a piece of work in 40 days. He works at it for 8 days and then y finished it in 16 days. How long will they together take to complete the work? Select one: a. 25days b. 16 days c. 50 days d. 13 1/3 days

Answer 1

X can complete work in 40 days. So he does 1/40th of the full work in 1 day

So in 8 days he does 8/40 =1/5th of the work
Remaining 4/5th if the work Y finish in 16 days. So the portion of the work he does in one day = (4/5) / 16 =1/20

So the portion of the work X and Y do together in one day is 1/40 + 1/20
= 3/40

So the number of days they needed together is 40/3 or 13 1/3