A can do a piece of work in 4 days and B can complete the same work in 12 days. What is the number of days required to do the same work together?
Correct Answer: 3 days
Explanation:
A 's 1 day's work = 1/4
B ' s 1 days's work = 1/12
(A+B) ' s day ' s work = 1/4 + 1/12
= (3 + 1)/12 = 4/12 = 1/3
Days required by A and B together to do the work = 1 / (A + B ) ' s day ' s work = 3 days
