Question

A can do a piece of work in 4 hours and B in 12 hours. After B has worked for 4 hours, he is joined by A. how loona will A and B will take to complete it?​

Answer 1

Answer:

A's one hr. work=1/4

B's one hr.work=1 / 12

B, S.4 hrs work=4/12

Balance = 8/12

A&B's hr.work=.I/4+1/12 = 4/12 = I/3

A&B complete 8/12x3/1=2 hrs