Question

A can do a piece of work in 80 days. He works at it for 10 days & then B alone finishes the remaining work in 42 days. In how much time will A and B, working together, finish the work?

Answer 1

Ajay can do part of park in 1 day=1/80
Work done by ajay in 10 days=10/80
=1/8
Remaining work=1-1/8
=7/8
B complete in 42 days=7/8part of work
B can complete in1day=1/48part of work
So B alone can complete it in 48 days
Work done by both in 1 day
=1/80+1/48
=(3+5)/240
=1/30
So they can finish the work together in 30days

Answer 2

Answer:

Step-by-step explanation:

do part of park in 1 day=1/80

Work done by ajay in 10 days=10/80

=1/8

Remaining work=1-1/8

=7/8

B complete in 42 days=7/8part of work

B can complete in1day=1/48part of work

So B alone can complete it in 48 days

Work done by both in 1 day

=1/80+1/48

=(3+5)/240

=1/30

So they can finish the work together in 30days