This article will cover the A-Z of Data Sufficiency, covering the type and pattern of Data Sufficiency questions followed by few solved examples.
What is Data Sufficiency?
Data Sufficiency questions test your knowledge of basic math facts and skills coupled with reasoning, analytical and problem solving abilities. Each Data Sufficiency item presents you with a question where you need to decide whether or not the information presented along with the question would be sufficient to answer the question.
What makes Data Sufficiency questions different?
The challenge in DS questions, as they are popularly called, is not question solving but rather establishing whether the question has a solution or not. A special array of five answer choices is provided, each of which categorizes the relationship between the question and the information provided in a different way. You must select the answer choice that describes this relationship accurately.
Let's have a cursory look at these answer options which generally feature in this question type
Give answer (A) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
Give answer (B) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
Give answer (C) if the data either in Statement I or in Statement II alone are sufficient to answer the question.
Give answer (D) if the data even in both Statements I and II together are not sufficient to answer the question.
Give answer (E) if the data in both Statements I and II together are necessary to answer the question.
Learning
Solved Data Sufficiency Questions
Example 1: Is the product of two numbers greater than 100?
Solution: Let us analyse the individual statements first and then take them together.
Example 2: Is x a prime number?
Solution: Here the first statement is sufficient to answer the question as we see that there is no prime number between 91 <x< 97. Hence 'x' is not a prime number.
In second statement, the factors of 121 are 1, 11 and 121. Here 1 and 121 are not prime numbers whereas 11 is a prime number. Hence in this case 'x' may or may not be a prime number. Hence, only the first statement is sufficient to solve the question. Option A is the answer.Learning
Example 3: Is x = - 5?
Solution: Here the question directly asks whether x is equal to - 5 or not.
Data Sufficiency: Key Learning