
GMAT Data Sufficiency questions are a key part of the GMAT Data Insights section. These questions test your ability to determine whether the information provided is enough to answer a question. Instead of solving a problem all the way through, you must decide if the information you have is sufficient to find the answer. This tests your logical reasoning and ability to handle complex problems quickly.
In this blog, you’ll find a simple rule PDF, a set of practice questions with answers, and a few additional problems to help you build confidence before the exam. You’ll also learn about common mistakes that students make and tips to save time. You also take the GMAT mock test to understand the exam pattern and type of questions.
The key to solving Data Sufficiency questions is knowing when you have enough information. Here are some basic rules that will help you navigate these questions:
You can download the full rules PDF from the link above. Here’s a quick overview of the main ones:
| Concept | Formula |
|---|---|
| Data Sufficiency Basics | Determine if the information provided is enough to answer the question without solving the problem fully. |
| Combining Statements | If one statement alone is insufficient but combining both provides a solution, use both statements. |
| Yes/No Questions | If a statement answers with "Yes" or "No", check if both provide sufficient information to answer the question. |
| Evaluating Statements | Individually evaluate each statement before combining them to check sufficiency. |
| Logical Relationships | Look for logical links between numbers and variables to assess sufficiency. |
| Statements Not Sufficient | If one or both statements don’t provide enough data, the answer is often "Insufficient". |
| Eliminating Choices | Eliminate answer choices that suggest insufficient data when both statements do not provide enough information. |
Students often make small mistakes in Data Sufficiency questions, which can cost valuable time or lead to incorrect answers. Here are some common errors to watch out for:
Misunderstanding the Question: Students sometimes forget that Data Sufficiency questions don’t require solving. They only ask if the information is enough to find an answer. Don’t solve the problem fully, just determine if the data is sufficient.
Jumping to Conclusions Too Quickly: Don't assume one statement is enough too soon. Always double-check whether the data is truly sufficient before answering.
Combining Statements Too Early: Be cautious when combining statements. Make sure the information from both statements creates a clearer path to the answer.
Not Analysing Both Statements: Always evaluate both statements separately and together. Often, one statement might be insufficient, but together they provide the necessary data.
Forgetting to Look for Logical Links:In Data Sufficiency questions, sometimes the relationship between numbers or statements is important. Check for links that can help you determine sufficiency.
Here’s a short set of GMAT Data Sufficiency questions to help you practice. They include all common types: checking sufficiency, combining statements, and handling yes/no questions. Practice these often to improve your speed and accuracy before your GMAT test.
x is the simple interest, y is the compound interest (compounded annually) on capital P at the same rate of interest for two years. What is the value of P?
Statament 1: y - x = 20
Statement 2: y + x = 1620
correct answer:- 3
How many marks did Arun secure in English?
Statement 1: The average marks obtained by Arun in four subjects, including English, are 60.
Statement 2: The total marks obtained by him in English and Mathematics together are 100, and the total marks obtained by him in Mathematics and Science together are 160.
correct answer:- 5
What is the train's speed if the train's length is 240 metres?
Statement I: The train crosses a pole in 24 seconds.
Statement 2: The train crosses a platform in 48 seconds.
correct answer:- 1
Sri Gupta borrowed a sum at simple interest. What is the total amount returned in 2 years?
Statement 1: The simple interest incurred on the sum in 1 year is Rs 600.
Statement 2: The borrowed sum is ten times the amount earned as simple interest in two years.
correct answer:- 3
How many students are there in the class?
Statement 1: There are more than 22 but less than 36 students in the class.
Statement 2: If students of the class are divided into groups, each group has exactly 11 students.
correct answer:- 3
Is it 9 o'clock now?
Statement 1: After half an hour, the minute and the hour hands of the clock will make an angle of exactly 90 degrees with each other.
Statement 2: Exactly 15 minutes ago, the hour and the minute hands of the clock coincided with each other.
correct answer:- 4
What is the percentage of interest rate per annum?
Statement I: The ratio of compound interest and simple interest earned in the second year at the same rate on the same principal is 5 : 4.
Statement 2: The amount becomes Rs. 19,500/- in the three years on simple interest.
correct answer:- 1
What is the speed of the train in kmph?
Statement 1: The train crosses a 420 metre-long platform in 12 seconds.
Statement 2: The train crosses a single pole in 8 seconds.
correct answer:- 3
How many students passed in the first class?
Statement 1: 85% of the students who appeared in the examination have passed with either first class, second class, or in the pass class.
Statement 2: 750 students have passed in the second class. The number of students who passed in the pass class is 28% of those who passed in the second class.
correct answer:- 5
What is the amount invested in Scheme B?
Statement I: The amount invested in Schemes ‘A’ and ‘B’ is in the ratio of 2:3, respectively.
Statement 2: The amount invested in Scheme ‘A’ is 40% of the total amount invested.
correct answer:- 5
In a partnership business, A, B and C, what profit did B get at the end of 2 years?
Statement 1: A and B started the business by investing in a ratio of 3:5. C joined after 6 months with Rs. 4 lakhs.
Statement 2: After two years, A’s share in profit was Rs. 60000.
correct answer:- 3
What is the total number of students in Course 'A' in College 'X'?
Statement 1: The respective ratio of girls and boys is 2 : 3.
Statement 2: The number of students has grown by 5% this year compared to 4% last year, from the number 1000, which was the year before last.
correct answer:- 5
What was the grand total of the Falcon Team of College ‘X’?
Statement 1: Mayank correctly remembers that Falcon Team scored a grand total of above 82 but below 91.
Statement 2: Animesh correctly remembers that Falcon Team scored a grand total of above 77 and below 84.
correct answer:- 3
How much profit was earned by selling a product for Rs 100/-?
Statement 1: Profit would have been 20% if it had been sold for Rs 90/-.
Statement 2: The profit was one-third of the purchase price.
correct answer:- 4
The difference between the two digits of a number is 6. What is the number?
Statement 1: The digit at the unit place is bigger than the other digit
Statement 2: The sum of two digits is 12.
correct answer:- 3
What is the two-digit number?
Statement 1: The difference between the two digits is 9.
Statement 2: The sum of the digits is equal to the difference between the two digits.
correct answer:- 1
What is the principal amount?
Statement 1: The difference between simple interest and compound interest for 2 years at the same rate on the same principal is Rs. 37.50
Statement 2: Simple interest for 3 years is Rs. 2,250
correct answer:- 3
If a, b, c are positive integers, then find the value of $$\dfrac{a^5b^3c^2}{a^4b^6c^2}$$
Statement 1: a = 1
Statement 2: b = 1
correct answer:- 3
Find the value of x?
Statement 1: 2x+3y = 12
Statement 2: 3x+8y = 24
correct answer:- 3
Find the value of x+2y?
Statement 1: 4x+8y = 24
Statement 2: 3x+8y = 9
correct answer:- 1
Find the SP of the article.
Statement 1: The MP of an article is 140, and the article is sold at a 10% discount.
Statement 2: The markup percentage is 40% and the discount is 10%.
correct answer:- 1
Is X > Y?
Statement 1: The selling prices of a pen and a pencil are 2 and 3 rupees, respectively. Ramu bought X pens, Y pencils, which cost him Rs 36.
Statement 2: The length of the hypotenuse of a right-angle triangle with sides X and Y is 10.
correct answer:- 3
How many students are there in the class?
Statement 1: More than 20 but fewer than 27 students are in the class.
Statement 2: More than 24 but fewer than 31 students are in the class. When the students are divided into groups, each group contains five students.
correct answer:- 3
How many students scored more than B in a class of 25 students?
Statement 1: More than four but less than ten students scored more than that of B. B’s rank is an odd number. Seventeen students scored less than D.
Statement 2: The rank of C is 16th from the last. B got more marks than C. Only two students were there, between B and C.
correct answer:- 2
What is the two-digit positive number?
Statement 1: The sum of the two digits of the number is 8.
Statement 2: The sum of the two digits is 3 more than the higher digit.
correct answer:- 5
Is the sum of integers x and y greater than 85?
Statement 1: The product of x and y is greater than 85.
Statement 2: One of the variables is greater than 83.
correct answer:- 3
How many marks did Soham score in an examination consisting of 10 compulsory questions each of 10 marks and having no negative marking?
Statement I: Soham did not have a two digit score and he correctly attempted atleast 1 question.
Statement II: Soham would've scored below 60 if he got 3 more questions wrong as compared to present.
correct answer:- 1
What was the total compound interest on a sum after three years?
Statement 1: The interest after one year was Rs. 100/-, and the sum invested was Rs. 1,000/-
Statement 2: The difference between simple and compound interest on a sum of Rs. 1,000/- at the end of two years was Rs. 10/-.
correct answer:- 4
What is the speed of the boat in still water?
Statement 1: It takes 2 hours to cover the distance between A and B downstream.
Statement 2: It takes 4 hours to cover the distance between A and B upstream.
correct answer:- 5
What is the value of 144 $ 16 *7 # 9 ?
I. ‘$’ means ‘÷’, ‘*’ means ‘x’ and ‘#’ means ‘+’.
II. 16 $ 4 *2 # 2 =10.
correct answer:- 1
A box contains oranges, bananas and apples. How many apples are there in the box?
Statement 1: Of the hundred fruits in the box, fifty percent constitute oranges and bananas together.
Statement 2: Fifty percent of the fruits in the box are apples.
correct answer:- 1
Brinda’s merit rank is 17th in her class. What is her rank from the last?
Statement 1: There are 70 students in her class.
Statement 2: Nisha, who ranks 20th in Brinda’s class, is 51st from the last.
correct answer:- 4
What is the percentage of interest rate per annum for the money invested under simple interest?
Statement 1: Simple interest earned in 3 years is Rs. X.
Statement 2: The amount increases by 80% in 5 years.
correct answer:- 2
How many children are there in the class?
Statement 1: Boys and girls are in the ratio of 8:5, respectively, and the number of girls is less than that of boys by 24.
Statement 2: The number of girls in the class is 40
correct answer:- 1
What is the two-digit number?
Statement 1: The difference between the digits is 7.
Statement 2: The sum of the digits is 11.
correct answer:- 5
How much time will Ravindra take to complete one round, cycling around the boundary of a circular ground?
Statement 1: Speed of cycling is 12 kmph.
Statement 2: The diameter of the ground is 700 metres.
correct answer:- 3
A shopkeeper had a weight balance in which weights were kept on only one side. All the weights were different in kg and were integers. How many weight blocks did he have?
Statement 1: The maximum weight he could weigh was 15 Kg.
Statement 2: With a specific set of weights, he could measure every weight from 1 kg to 15 kg, and each weight had exactly one unique combination of those weights.
correct answer:- 3
How many students were selected for the competition from the class of 10 students?
Statement 1: The number of ways in which the students can be selected for the competition is 45.
Statement 2: The number of people selected for the competition is less than the number of people who got rejected.
correct answer:- 3
What is Mohit’s rank in the marathon?
Statement 1: Out of the total 80 participants, there are 5 people between Mohit and Sameer, who have got rank 7 from the top.
Statement 2: Out of 92 participants, there were 9 people who finished the race after Mohit.
correct answer:- 2
How many pages of the book did Mayank read till Wednesday?
Statement I: It was a 300-page book, and Mayank started reading from Monday of the same week, with an average read of 50 pages per day.
Statement 2: It was a 300-page book, and Mayank read the last 75 pages on Thursday of the same week.
correct answer:- 2
Which train did Harish catch to go to the office?
Statement 1: Harish missed his usual train of 10.25 a.m. A train comes in every 5 minutes.
Statement 2: Harish did not catch the 10.40 a.m. train or any train after that time.
correct answer:- 5
What is the rate of interest?
Statement 1: Simple interest obtained on the sum of 25000 in 2 years is 250 less than the interest obtained from compound interest during the same time.
Statement 2: Simple interest obtained in 10 years is equal to the original sum.
correct answer:- 4
What is the number of plants planted in columns and rows in the field?
Statement 1: The number of columns is 4 more than the rows.
Statement 2: In each column, the number of trees is even.
correct answer:- 5
What is the present age of the father?
Statement 1: The present age of the father is five times the present age of his son.
Statement 2: 5 years ago age of the father was 15 times the age of his son.
correct answer:- 3
Of the salary, Manoj spends 20% on transport, 30% on food, 35% is saved, and the remaining is spent on entertainment. What amount of the total salary does Manoj spend on entertainment per month?
Statement I: He spends Rs. 5000 on food for one month.
Statement 2: He saves Rs. 3500 per month of his total salary.
correct answer:- 4
What is the value of (x*y) given that both x and y are integers?
Statement I
: LCM is 20 times the HCF.
Statement II
: HCF of x and y is 30.
correct answer:- 3
GMAT Data Sufficiency questions assess your ability to determine if the given information is enough to answer a question, without solving the entire problem.
Focus on evaluating the statements for sufficiency rather than solving the problem fully. Check both individual statements and their combination.
Common mistakes include misunderstanding the question, jumping to conclusions, combining statements too early, and not analysing both statements.
Always ensure that the provided data is sufficient before answering, and double-check whether the combination of statements is helpful.
Yes, you only need to assess whether the data provided is sufficient to answer the question, not solve it fully.
The main rule is to determine if the information provided is enough to answer the question, using both individual and combined statements.
Practice regularly with different question types and focus on understanding the sufficiency of information rather than solving the problem completely.
Familiarise yourself with the common question types and practice identifying sufficient data quickly to improve accuracy and speed.