A and B can do a work in 8 days, B and C in 12 days and A, B, C together in 6 days. In how many days can A and C together complete the work? MCQ with Answer and Explanation
A and B can do a work in 8 days, B and C in 12 days and A, B, C together in 6 days. In how many days can A and C together complete the work?
A. 8 days
B. 10 days
C. 4 days
D. 6 days
Answer: Option A
Solution (By JKSSB Mock Tests)
Total work = LCM(8, 12, 6) = 24 units. Efficiency of (A+B) = 3, (B+C) = 2, (A+B+C) = 4. Efficiency of C = (A+B+C) - (A+B) = 4 - 3 = 1. Efficiency of A = (A+B+C) - (B+C) = 4 - 2 = 2. Combined efficiency of A and C = 2 + 1 = 3. Time taken by A and C together = 24 / 3 = 8 days.
Explanation:
Let efficiency of C = 1, then B = 2 and A = 4. Combined efficiency = 1 + 2 + 4 = 7 units/day. Total work = 4 * 7 = 28 units. Time taken by C alone = 28 / 1 = 28 days.
No comments yet. Be the first to start the discussion!