Data Sufficiency

Data Sufficiency

Data sufficiency reasoning is part of quantitative aptitude. In the data sufficiency reasoning, one question is followed by different statements. Candidates have to determine if the statement is required for answering the question.

This is the part of the reasoning and no calculation is needed here to find out the answer. Candidates have to find out the answer from the given data. Data sufficiency contains different types of questions such as SI (Simple Interest) and CI (Compound Interest) based questions. 

Concept of data sufficiency reasoning

Data sufficiency reasoning is related to data interpretation. Candidates need to check if the given data is sufficient to do the answer. There are two to three statements followed by one statement and candidates have to find out the proper data interpretation from the given data. There is no calculation needed, just candidates have to interpret the data to find out a suitable answer. Candidates need to find a unique answer. 

Different types of data sufficiency reasoning

  • Number system
  • Geometry
  • Algebra
  • Mensuration
  • Profit & loss
  • Percentage
  • Permutation and Combination
  • Time, Speed & distance    

Steps to solve data sufficiency reasoning

This is very important to practice more and develop reasoning skills. For solving the data sufficiency reasoning, candidates have to maintain some steps. Such as:

Do not waste time solving the problem

Data sufficiency reasoning does not want the solution of the problem; rather, it is about determining if the given data is sufficient or not for solving the problem. Candidates should not start to solve the problem.

“Memorise the answer choices”

More practice can help the candidate to speed up and they can memorise the same pattern of questions.

Consider the statement individually

The candidates will focus on individual statements and try to understand if it gives enough information or not. They have to analyse the statement alone.

Be sure about the solution

Candidates should be sure that the answer is sufficient to support the question.

Brush up basic reasoning skill

Candidates should know the basic knowledge of maths and reasoning. A good grasp of the mental ability of maths can speed up problem-solving skills.   

Data sufficiency reasoning questions and answers

There are some data sufficiency reasoning questions and answers to clear the concept of data sufficiency reasoning. Such as:

Question 1: Is Y < 9?

Statement 1: Sea is blue

Statement 2: Y=4

Here it is obvious that Y is less than 9 and the given information is sufficient to conclude. 

Question 2: “What is the distance between Chandigarh and Delhi?”

Statement 1: “Karnal is 130 km from Chandigarh”

Statement 2: “Delhi is 120 km from Karnal”

The answer will be based on two assumptions such as that Chandigarh, Delhi, and Karnal are in a straight line and Karnal is situated between Chandigarh and Delhi. Candidates cannot get a suitable answer after combining two statements. One can conclude by saying that this data is not sufficient to find out a conclusion. 

These data sufficiency reasoning questions and answers can give the insight to find out the conclusion.

Possible options to find a conclusion

  • There are some possible options based on the two statements. These are:
  • Statement 1 is sufficient, but only 2 is not sufficient
  • Statement 2 is sufficient, but only 1 is not sufficient
  • Both statements are sufficient together but the individual statement is not sufficient
  • “Each statement alone is sufficient”
  • Neither statement 1 nor statement 2 is sufficient
  • Steps to solve the question quickly
  • Do not try to find out a proper answer
  • Avoid guessing
  • Interpret individual statements to find a solution
  • Try to find out if the given information is sufficient or not 
  • Do not try to solve the problem
  • Do not try to find out the exact value
  • Do not try to understand if it is true or false
  • Try to support the question with the given statement


Data sufficiency reasoning helps to solve the question based on mental ability and problem-solving skills. It is logical reasoning and it helps to improve problem-solving skills. There are two basic types of data sufficiency questions such as yes/no question and value question. Candidates have to determine if the given data can present a suitable answer.