A and B together can complete some work in 24 days. If A, B and C work together, they can complete the same work in 18 days. B and C both have the same efficiency.

Correct answer is '16'. Can you explain this answer?

NISTHA DHOLAKIA
Jan 31, 2020 |

We know that, A, B and C require 36, 72 and 72 days respectively to complete the work when working alone.

From the solution to the previous question, total work = 72 units and the efficiency of A, B and C (in units/day) is 2, 1 and 1 respectively.

Since the efficiency of D is the same as that of A, d = 2 units/day as well.

A, B and C work together for the first 6 days.

So, amount of work done in the first 6 days = 6(a + b + c) = 6(2 + 1 + 1) = 24 units.

Now, C leaves and D joins the work.

So, the remaining 48 units of work is done by A, B and D.

Let the number of days taken by these three people by x.

So, 48 = (2 + 1 + 2) * x

x = 48/5 = 9.6 days

Since the work is incomplete at the end of day 9, the number of days taken has to be considered as 10.

So, total time taken to complete the work = 6 + 10 =16

Answer: 16

We know that, A, B and C require 36, 72 and 72 days respectively to complete the work when working alone.From the solution to the previous question, total work = 72 units and the efficiency of A, B and C (in units/day) is 2, 1 and 1 respectively.Since the efficiency of D is the same as that of A, d = 2 units/day as well.A, B and C work together for the first 6 days.So, amount of work done in the first 6 days = 6(a + b + c) = 6(2 + 1 + 1) = 24 units.Now, C leaves and D joins the work.So, the remaining 48 units of work is done by A, B and D.Let the number of days taken by these three people by x.So, 48 = (2 + 1 + 2) * xx = 48/5 = 9.6 daysSince the work is incomplete at the end of day 9, the number of days taken has to be considered as 10.So, total time taken to complete the work = 6 + 10 =16Answer: 16

Do you know? How Toppers prepare for CAT Exam

With help of the best CAT teachers & toppers, We have prepared a guide for student who are
preparing for CAT : 15 Steps to clear CAT Exam