Question : A and B together can complete a piece of work in 18 days, B and C in 24 days, and A and C in 36 days. In how many days, will all of them together complete the work?
Option 1: 16 days
Option 2: 15 days
Option 3: 12 days
Option 4: 10 days
Correct Answer: 16 days
Solution : 1 day work of A and B = $\frac{1}{18}$ ---------(1) 1 day work of B and C = $\frac{1}{24}$ ---------(2) 1 day work of A and C = $\frac{1}{36}$ ---------(3) Adding equations (1), (2) and (3), we get: ⇒ 2 × (A + B + C) = $\frac{1}{18}+\frac{1}{24}+\frac{1}{36}$ LCM of (18, 24, 36) = 72 ⇒ 2 × (A + B + C)'s 1 day work = $\frac{4+3+2}{72}=\frac{1}{8}$ ⇒ (A + B + C)'s 1 day work = $\frac{1}{8×2}=\frac{1}{16}$ So, A, B, and C can work together in 16 days. Hence, the correct answer is 16 days.
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Question : Vijay and Sahil together complete a piece of work in 40 days, Sahil and Ranjit can complete the same work in 48 days and Ranjit and Vijay can complete the same in 60 days. In how many days can all three complete the same work while working together?
Option 2: 24 days
Option 3: 32 days
Option 4: 38 days
Question : Tapas works twice as fast as Mihir. If both of them together complete a work in 12 days, Tapas alone can complete it in:
Option 1: 15 days
Option 2: 18 days
Option 3: 20 days
Option 4: 24 days
Question : A, B and C together can complete a work in 20 days. A and B together can complete the same work in 30 days. Then, C alone can complete the same work in how many days?
Option 1: 10 days
Option 2: 30 days
Option 3: 45 days
Option 4: 60 days
Question : 24 men can complete a work in 15 days. How many men are needed to complete the same work in 10 days?
Option 1: 16
Option 2: 20
Option 3: 36
Option 4: 25
Question : A and B can do a piece of work in 10 days. B and C can do it in 12 days. C and A in 15 days. In how many days will C finish it alone?
Option 1: 24 days
Option 3: 40 days
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