Data Sufficiency - Quant/Math - CAT 2013

Question 4 the day: August 09, 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:

In which year was Raghavan born?

1. Sundar who is older than Raghavan by one and a half years was born in the year 1958.
2. Raghavan turned 18 years in the year 1978.

Solution:

We have to find a conclusive answer for the question as to the year in which Raghavan was born.

From Statement A: We know that Sundar was born in 1958. And that he is 1 year and 6 months older than Raghavan. If Sundar was born before the month of July in 1958, then Raghavan’s year of birth would be 1959 (which is 1 year and 6 months from the first half of 1958). On the contrary, if Sundar was born after July 1958, then Raghavan’s year of birth would be 1960. Hence from this statement we cannot conclusively find out the year in which Raghavan was born.

From Statement B: Raghavan turned 18 year in the year 1978. If Raghavan turned 18 years in 1978, then wen can conclusively state that he was born in 1960. Therefore, statement B alone is sufficient to answer the above question.

Hence the correct answer is (1)