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

Redeem

If x is not equal to 0 and x^y=1, then which of...

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 2505
Joined: Sun Oct 15, 2017 1:50 pm
Followed by:6 members

If x is not equal to 0 and x^y=1, then which of...

by BTGmoderatorLU » Tue Dec 19, 2017 11:01 am
If x is not equal to 0 and x^y=1, then whcih of the following must be true?

I. x=1
II. x=1 and y=0
III. x=1 or y=0

A. I only
B. II only
C. III only
D. I and III only
E. None

The OA is E.

I'm confused with this PS question. Please, can any expert assist me with it? Thanks in advanced.
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Tue Dec 19, 2017 12:22 pm
Hi LUANDATO,

We're told that X is NOT equal to 0 and X^Y=1. We're asked which of the following MUST be true. When a question asks what MUST be true, what it's really asking is "which of the following is ALWAYS TRUE no matter how many different examples you can come up with."

This question is a great 'concept question', meaning that you don't have to do much math to answer it IF you recognize the concepts involved. Since X cannot be 0, there are three possible ways for X^Y to equal 1.
1) X=1 and Y could be ANY value.
2) Y=0 and X could be any value except 0.
3) X = -1 and Y is an EVEN integer.

Since any of these situations will lead to a value of 1, none of them individually must be true. The three Roman Numerals are:

I. x=1
II. x=1 and y=0
III. x=1 or y=0

None of these 3 options is always true.

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Sun Nov 10, 2019 10:15 pm

by Gaylyder » Sun Nov 10, 2019 10:36 pm
An important example for this question is just here. If you have any idea then you also share about this https://www.aussiessay.com/ page which only related with the page information. As you can check those things which are really good then you must have an idea about them.
Top
Post new topic Post Reply
• Page 1 of 1