GMAT Data Insights: Data Sufficiency 3

Question 1

What is the value of x? (1) 2x + 3 = 11 (2) x is positive

Accepted Answer

Statement (1) alone is sufficient

Answer

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

Accepted Answer

Both together but neither alone

Answer

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

Accepted Answer

Statement (1) alone is sufficient

Answer

Average equals sum divided by count, so 60/5=12 from (1) alone.

Question 4

Is xy > 0? (1) x > 0 (2) y > 0

Accepted Answer

Both together but neither alone

Answer

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

Accepted Answer

Both together but neither alone

Answer

If 60% are girls then 40% are boys, and 12 boys = 40% gives a total of 30.

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