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

Redeem

X and Y both positive?

Expert replies
Source: — Data Sufficiency |

by 2010gmat » Wed Nov 18, 2009 7:04 am
i have seen a similar question where 1. is 2x - 2y = 1 .... are your sure 1. says 2x.2y = 1???
Join the discussion

by sreak1089 » Wed Nov 18, 2009 7:28 am
I am not able to figure out what a) means in this question.....
Join the discussion

by chipbmk » Wed Nov 18, 2009 8:32 am
2010gmat wrote:i have seen a similar question where 1. is 2x - 2y = 1 .... are your sure 1. says 2x.2y = 1???
You are correct, it is 2x-2y = 1 ... I dont know what happened when I copied and pasted it.

Solutions?
Join the discussion

by sreak1089 » Wed Nov 18, 2009 8:52 am
Qn: Are x & y both +ve?

Stmt # 1: 2x - 2y = 1
=> 2(x-y) = 1
=> x-y = 1/2
it means (x-y) > 0
we can further deduce that x > y

This is still NOT SUFFICIENT as x & y can both be +ve or can both be -ve.

Stmt # 2: x/y > 1

Two cases exist: a) x & y both +ve with x > y
b) x & y both -ve with x < y

This is still NOT SUFFICIENT as x & y can both be +ve or both can be -ve.

Combining 1 & 2, we have can only have one case which is x & y both +ve with x > y.
Hence the answer is C
Join the discussion