Question

While working 7 h a day, a alone can complete a piece of work in 6 days and b alone in 8 days. in what time would they complete it together, working 8 h a day?

Answer 1

A can complete the work in 7*6 = 42 hours;
1 hour's work of A = 1/42;
B can complete the work in 7*8 = 56 hours;
1 hour's work of B = 1/56;
(A+B)'s 1 hour's work = 1/42+1/56 = 98/42*56;
(A+B) will take time to complete whole work,
working 7 hours a day = 42*56/98 = 24 hours;
Let X be the no. of days taken, working 8 hours a day to complete the work by A and B together.
Now, using work equivalence method ;
24 = 8*X;
X = 24/8 = 3 days.
ANSWER =3 DAYS