A group of men decided to do a work in 10 days, but 5 of them became absent. If the rest of the group did the work in 12 days, find the original number of men. MCQ with Answer and Explanation
A group of men decided to do a work in 10 days, but 5 of them became absent. If the rest of the group did the work in 12 days, find the original number of men.
A. 30
B. 35
C. 40
D. 25
Answer: Option A
Solution (By JKSSB Mock Tests)
Let the original number of men be x. Using M1 * D1 = M2 * D2: x * 10 = (x - 5) * 12 => 10x = 12x - 60 => 2x = 60 => x = 30.
A can finish a work in 12 days and B can do it in 15 days. After A had worked for 3 days, B also joined him to finish the remaining work. In how many days was the remaining work completed?
Explanation:
Total work = LCM(12, 15) = 60 units. Efficiency of A = 5, B = 4. In 3 days, A completed 3 * 5 = 15 units. Remaining work = 60 - 15 = 45 units. Combined efficiency of A and B = 5 + 4 = 9 units/day. Time taken for remaining work = 45 / 9 = 5 days.
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