SSC CGL – Combined Graduate Level Examination · Question 68
P can complete a task in 6 days, Q can destroy it in 4 days. P works for 3 days, then Q joins for 2 days. In how many days will P finish the remaining work alone?
Show answer & explanation
Answer: (C) 4 days
Explanation
After 3 days, 1/2 is done; the next 2 days change it by 2(1/6 − 1/4) = −1/6, leaving 1/3 done. P needs 2/3 ÷ 1/6 = 4 days.