Question

a can finish a task in 15 days while B can finish the same task in 20 days . if both of them together for 4 day , what fraction of work is left unfinished​

Answer 1

Answer:

wrk done in one day by A

1/15

wrk done by B in one day

1/20

wrk done by both in 1 day

1/15+1/20

7/60

wrk done by both in 4 days

7/60*4=7/15

wrk left=1-7/15

8/15