Question

John does ½ piece of work in 3 hours, Joe does ¼ of the remaining work in 1 hour and George finishes remaining work in 5 hours. How long would it have taken the three working together to do the work?

A A Correct Answer Incorrect Answer
B B Correct Answer Incorrect Answer
C C Correct Answer Incorrect Answer
D D Correct Answer Incorrect Answer

Solution

John can do 1/2 work in 3 hours, So he can complete entire work in 6 hours. Remaining work = 1- 1/2 = ½ Joe does 1/4 of the remaining work i.e 1/8 work in 1 hour, So he can complete entire work in 8 hours. Now remaining work = 3/8 George finishes remaining work in 5 hour. George do 3/8 work in 5 hours, So he can complete entire work in 40/3 hours. If all three work together, then, 1/6 + 1/8 + 3/40 = 30/11 So, the answer would be option d) 2(8/11) hours

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