A, B and C can complete a work in 10, 12 and 15 days respectively. They start working together. Find the number of days required to complete the work. MCQ with Answer and Explanation
A, B and C can complete a work in 10, 12 and 15 days respectively. They start working together. Find the number of days required to complete the work.
A. 4 days
B. 5 days
C. 3 days
D. 6 days
Answer: Option A
Solution (By JKSSB Mock Tests)
Total work = LCM(10, 12, 15) = 60 units. Efficiency of A = 6, B = 5, C = 4. Combined efficiency = 6 + 5 + 4 = 15 units/day. Time taken = 60 / 15 = 4 days.
A can finish a work in 18 days and B can do the same work in half the time taken by A. Then, working together, what part of the same work can they finish in a day?
X can do a piece of work in 40 days. He works at it for 8 days and then Y alone finishes the remaining work in 16 days. How long will X and Y together take to complete the work?
Explanation:
Let total work be 40 units. Efficiency of X = 1 unit/day. In 8 days, X completes 8 units. Remaining work = 40 - 8 = 32 units. Y finishes 32 units in 16 days, so Y's efficiency = 32 / 16 = 2 units/day. Combined efficiency of X and Y = 1 + 2 = 3 units/day. Time taken together = 40 / 3 = 13(1/3) days.
No comments yet. Be the first to start the discussion!