A, B and C working alone can complete a work in 10, 15 and 30 days respectively. In how many days A, B and C together can complete 30 percent of the same work?
Show answer & explanation
Correct answer: A
Explanation
A's one-day work = 1/10
B's one-day work = 1/15
C's one-day work = 1/30
Combined one-day work of all three -
= 1/10 + 1/15 + 1/30
= 3/30 + 2/30 + 1/30
= 6/30
= 1/5
Time to complete the work = 5 days
Time to complete 30% of the work = 30/100 × 5 = 3/2 days