Work Time Practice

This aptitude practice question is a Work Time problem solving question. Concept tested: Time taken by a group of people with different efficiencies to complete a task.

Question

Ram completes 60% of a task in 15 days and then takes the help of Rahim and Rachel. Rahim is 50% as efficient as Ram is and Rachel is 50% as efficient as Rahim is. In how many more days will they complete the work?

1. 13\\frac{1}{3})
2. 8\\frac{1}{3})
3. 5\\frac{5}{7})
4. 7\\frac{5}{7})

  Correct Answer      Choice (3). They will complete the work in 5\\frac{5}{7}) more days.

Explanatory Answer

Ram completes 60% of the task in 15 days.
i.e., he completes 4% of the task in a day.

Rahim is 50% as efficient as Ram is.
Therefore, Rahim will complete 2% of the task in a day.

Rachel is 50% as efficient as Rahim is.
Therefore, Rachel will complete 1% of the task in a day.

Together, Ram, Rahim and Rachel will complete 4 + 2 + 1 = 7% of the work in a day.
Ram, working alone, had already completed 60% of the task.
They have another 40% of the task to be completed.
Therefore, they will take \\frac{40}{7}) or 5\\frac{5}{7}) more days to complete the task.

  The correct answer is Choice (3).