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.
If x is not equal to 0 and x^y=1, then which of...
This topic has expert replies
-
- Moderator
- Posts: 2209
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
GMAT/MBA Expert
- [email protected]
- 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
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
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
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.