CAT Quantitative Aptitude Questions | CAT Time and Work questions

The question is from Time and work. Details about efficiency of two people is given we need to find out the efficiency of one person. A simple Work and Time question that makes you think !!

Question 8: B takes 12 more days than A to finish a task. B and A start this task and A leaves the task 12 days before the task is finished. B completes 60% of the overall task. How long would B have taken to finish the task if he had worked independently?

1. 48 days
2. 36 days
3. 28 days
4. 32 days

Video Explanation

Explanatory Answer

Method of solving this CAT Question from Pipes Cisterns and Work Time: A simple Work and Time question that makes you think !!

Let us say A and B split their share of the task and started doing their respective shares simultaneously.

Let’s say A takes A days to finish the task. Therefore, B takes A + 12 days to finish the entire task.

A has to finish 40% of the task, since B is doing the rest. So A will only take 2A/5 number of days.

B only has to finish 60% of the task, so B will take (3(A+12)/5) number of days.

But as we know, B starts working along with A and finishes 12 days after A stops working.

So, (3(A+12)/5) = ((2A)/5+12)
3A + 36 = 2A + 60
A = 24; B = 36 days.

The question is "How long would B have taken to finish the task if he had worked independently?"

Hence, the answer is "36 days".

Choice B is the correct answer.