Quantitative Aptitude – Time and Work – John takes twice as much time as Jack to finish

Slot – 2 – Quantitative Aptitude – Time and Work – John takes twice as much time as Jack to finish

Q. John takes twice as much time as Jack to finish a job. Jack and Jim together take one-thirds of the time to finish the job than John takes working alone. Moreover, in order to finish the job, John takes three days more than that taken by three of them working together. In how many days will Jim finish the job working alone?
Answer: 4

Solution:
Let the time taken by Jack to complete the work alone is x so that of taken by John alone = 2x
Let Jim takes y days complete it alone so as per question,
2x/3 = (x*y)/(x+y)
2x +2y = 3y
y = 2x
also it is given that
John takes three days more than that taken by three of them working together
So one day work for them
1/x+1/2x +1/2x = 4/2x = 2/x
Combined time for all three = x/2
Thus 2x – x/2 = 3
Or x = 2
Thus required time for Jim = 2x = 2*2 = 4

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