BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

When x and y are integers, is x an even number? 1) 2x+y is

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

When x and y are integers, is x an even number? 1) 2x+y is

by Max@Math Revolution » Thu Mar 17, 2016 5:24 pm
When x and y are integers, is x an even number?

1) 2x+y is an odd number.
2) 5x+3y is an odd number.


* A solution will be posted in two days.
Top
Source: — Data Sufficiency |
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

by Max@Math Revolution » Mon Mar 21, 2016 3:23 am
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

When x and y are integers, is x an even number?

1) 2x+y is an odd number.
2) 5x+3y is an odd number.


In the original condition, there are 2 variables(x,y), which should match with the number of equations. So you need 2 equations. For 1) 1 equation, for 2) 1 equation, which is likely to make C the answer.
When 1) & 2), 2x becomes even and y=odd. If y=odd, 5x+3y=odd -> x=even, which is yes and sufficient.
Therefore, the answer is C.
Top
Post new topic Post Reply
• Page 1 of 1