Data Sufficiency - Quant/Math - CAT 2008

Question 4 the day: September 18, 2002
The question for the day is a data sufficiency question. One important thing about Data Sufficiency questions is that more often than not these questions take you about 30 seconds to crack them. And it generally does not involve any difficult calculations which tend to take most of the time when you solve a problem. Here the question is about whether you can solve the problem with the information given and NOT about actually solving the problem.

In this question, there is a question statement which is followed by two statements. You have to decide whether the information provided in the two statements is sufficient for answering the question.

Mark 1

If the question can be answered by using one of the statements alone, but cannot be answered by using the other statement alone.

Mark 2

If the question can be answered by using either statement alone.

Mark 3

If the question can be answered by using both statements together, but cannot be answered by using either statement alone.

Mark 4

If the question cannot be answered even by using both the statements together.

Question:

Who is the fastest among the three workers a, b and c?

1. a and b together take 12 hours to complete a job
2. a, b and c working together can complete the job in 6 hours

Solution:

First statement gives no info about c.

From statement B we know that c takes 12 hours to complete the job which is the same as A & B together take to do the job. But either A or B need not have contributed to the work in which case there will two of them C and one of A or B who work equally efficiently.