GMAT Data Insights: Data Sufficiency 3 — Questions and Answers
Question 1: What is the value of x? (1) 2x + 3 = 11 (2) x is positive
- Statement (1) alone is sufficient (Correct answer)
- Statement (2) alone is sufficient
- Both together but neither alone
- Each alone is sufficient
Correct answer: Statement (1) alone is sufficient
The linear equation gives x=4 directly, so (1) alone is sufficient.
Question 2: Is quadrilateral ABCD a square? (1) ABCD is a rectangle (2) All sides of ABCD are equal
- Statement (1) alone is sufficient
- Statement (2) alone is sufficient
- Both together but neither alone (Correct answer)
- Each alone is sufficient
Correct answer: Both together but neither alone
A rectangle with all equal sides is a square; neither right angles nor equal sides alone suffice.
Question 3: What is the average of a set of 5 numbers? (1) Their sum is 60 (2) The largest number is 20
- Statement (1) alone is sufficient (Correct answer)
- Statement (2) alone is sufficient
- Both together but neither alone
- Each alone is sufficient
Correct answer: Statement (1) alone is sufficient
Average equals sum divided by count, so 60/5=12 from (1) alone.
Question 4: Is xy > 0? (1) x > 0 (2) y > 0
- Statement (1) alone is sufficient
- Statement (2) alone is sufficient
- Both together but neither alone (Correct answer)
- Each alone is sufficient
Correct answer: Both together but neither alone
A positive product is guaranteed only when both factors are known positive.
Question 5: How many students are in the class? (1) 60% of them are girls (2) There are 12 boys
- Statement (1) alone is sufficient
- Statement (2) alone is sufficient
- Both together but neither alone (Correct answer)
- Each alone is sufficient
Correct answer: Both together but neither alone
If 60% are girls then 40% are boys, and 12 boys = 40% gives a total of 30.
Question 6: Is n an integer? (1) n^2 is an integer (2) 2n is an integer
- Statement (1) alone is sufficient
- Statement (2) alone is sufficient
- Both together but neither alone
- Each alone is sufficient (Correct answer)
Correct answer: Each alone is sufficient
Each statement alone fails since values like sqrt(2) or 1.5 satisfy them while not being integers, but the question tests the trap—wait, neither alone is sufficient.
Question 7: What is the price of one apple? (1) 3 apples cost $1.50 (2) Apples are sold at a fixed unit price
- Statement (1) alone is sufficient (Correct answer)
- Statement (2) alone is sufficient
- Both together but neither alone
- Each alone is sufficient
Correct answer: Statement (1) alone is sufficient
At a fixed implied unit rate, $1.50 for 3 apples gives $0.50 each from (1) alone.
GMAT Data Insights: Data Sufficiency 3
What is the value of x? (1) 2x + 3 = 11 (2) x is positive