GMAT Question of the Day – DS – Number Properties

GMAT Question of the Day

GMAT Question of the Day – Data Sufficiency – Number Properties

If v is greater than or equal to 1 is r/v a terminating decimal?

(1) v – 1 is divisible by 3

(2) r = 99


GMAT Question of the Day Solution

A terminating decimal broken down to its simplest form only has 2’s and 5’s in the denominator. That’s because fractions are based on 10’s and 2’s and 5’s are the only prime factors of 10. Some examples of terminating decimals are 1/2, 2/5, 1/4, 1/8, 3/20, 7/100. Examples of non-terminating decimals are 1/3, 4/6, 1/9, 2/45, 5/70.

Statement (1) tells us that v could 4, 7, 10, 13, 16, 19… Any number that has a remainder of 1 when divided by 3. 10 works but 7 doesn’t so this is insufficient.

Statement (2) only tells us about the numerator so it must be insufficient.

Putting them together, a value of 10 for v will make a terminating decimal but a value of 7 for v will still result in a non-terminating decimal. Insufficient.