If 0 < a/b < 1 and 0 < a, what is the value of inte

This topic has expert replies
Moderator
Posts: 2205
Joined: Sun Oct 15, 2017 1:50 pm
Followed by:6 members
If 0 < a/b < 1 and 0 < a, what is the value of integer a?

(1) The least common denominator of a/b and 1/5 is 10
(2) b = 2

The OA is B.

I need help to solve this DS question. Please can any expert explain why that is the correct answer? Thanks.

User avatar
Legendary Member
Posts: 2663
Joined: Wed Jan 14, 2015 8:25 am
Location: Boston, MA
Thanked: 1153 times
Followed by:128 members
GMAT Score:770

by DavidG@VeritasPrep » Fri Nov 03, 2017 10:02 am
LUANDATO wrote:If 0 < a/b < 1 and 0 < a, what is the value of integer a?

(1) The least common denominator of a/b and 1/5 is 10
(2) b = 2

The OA is B.

I need help to solve this DS question. Please can any expert explain why that is the correct answer? Thanks.
Statement 1
Case 1: a =1 and b = 2. (the LCM of 2 and 5 is 10.)
Case 2: a = 3 and b = 10 (the LCM of 5 and 10 is 10.)
We can get more than one value for a, so this statement alone is not sufficient to answer the question.

Statement 2:
If a/b < 1, we know that if b = 2, a/2 < 1 and a < 2. We also know that a is positive. Well, there's only one positive integer less than 2, so a = 1. Sufficient. The answer is B
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save $100 off any live Veritas Prep GMAT Course