P and Q working alone can complete a work in 12 days and 24 days respectively. They work on alternate days one at a time. P works on the first day. In how many days the whole work will be completed?
Show answer & explanation
Correct answer: B
Explanation
Given:
P works alone = 12 days
Q works alone = 24 days
P works on the first day
P's rate per day = 1/12
Q's rate per day = 1/24
Work done in 2 days = 1/12 + 1/24 = 1/8
Work will be completed in 8 such cycles (of 2 days each)
Total time = 8 × 2 = 16 days