Question

answer for fourth question

Answer 1

time taken by A to do a piece of work=3hours
time taken by B to do a piece of work=2 hours
work done by a in one hr=1/3
time taken by B in 1 hour=1/2
time taken by A and B to do a piece of work=1/3-1/2
2-1/6
1/6
time taken by A and B to do a piece of work together=6