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A can do 50% more work as B can do in the same time, B alone can do a piece of work in 20 hours. A, with help of B, can finish the same work in how many hours?
- A12
- B8
- C13
- D15
Answer not set
Discussion 1
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CCommunity
Time required to complete the work for B = 20 hrs
∴ Work done by B in 1 hour = 1/20
Given A is 50% more efficient than B
∴ Work done by A in 1 hour = (3/2) × 1/20 = 3/40
∴ Work done by both A and B together in 1 hour = (3/40) + (1/20)
⇒ (3/40) + (1/20) = 5/40 = 1/8
⇒ Work done by both A and B in 1 hour = 1/8
∴ A and B can complete the work in 8 days
∴ Work done by B in 1 hour = 1/20
Given A is 50% more efficient than B
∴ Work done by A in 1 hour = (3/2) × 1/20 = 3/40
∴ Work done by both A and B together in 1 hour = (3/40) + (1/20)
⇒ (3/40) + (1/20) = 5/40 = 1/8
⇒ Work done by both A and B in 1 hour = 1/8
∴ A and B can complete the work in 8 days