Is \(x\) less than \(20?\)

This topic has expert replies
Moderator
Posts: 2058
Joined: Sun Oct 29, 2017 4:24 am
Thanked: 1 times
Followed by:5 members

Is \(x\) less than \(20?\)

by M7MBA » Fri Mar 19, 2021 7:16 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Is \(x\) less than \(20?\)

(1) The sum of \(x\) and \(y\) is less than \(20.\)
(2) \(y\) is less than \(20.\)

Answer: E

Source: GMAT Prep
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

Re: Is \(x\) less than \(20?\)

by Brent@GMATPrepNow » Sat Mar 20, 2021 5:36 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

M7MBA wrote:
Fri Mar 19, 2021 7:16 am
Is \(x\) less than \(20?\)

(1) The sum of \(x\) and \(y\) is less than \(20.\)
(2) \(y\) is less than \(20.\)

Answer: E

Source: GMAT Prep
Target question: Is x less than 20?

When I scan the two statements, I can quickly see that neither statement alone is sufficient.
So let's jump straight to....
.
.
.

Statements 1 and 2 combined
There are several values of x and y that satisfy BOTH statements. Here are two:
Case a: x = 5 and y = 5. In this case, the answer to the target question is YES, x is less than 20
Case b: x = 30 and y = -30. In this case, the answer to the target question is NO, x is not less than 20
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image