Question

a can do work in 15 days and b can do it in 20 days. they work together for 6 days and then a goes away. in how much days b will finish the remaining work​

Answer 1

1day's work of a=1/15

1days' s work of b=1/20

1day's work of both=7/60

6days work of both=7/10

remaining work=1-7/10=3/10

3/10 part of work can be completed by b in3/10×20/1

answer is 6 days