Solution:
If x = 1, y = 4^1 - 3 = 1.
If x = 2, y = 4^2 - 3 = 13.
If x = 3, y = 4^3 - 3 = 61.
If x = 4, y = 4^4 - 3 = 253.
We see that if x is an integer > 4, then y > 253. Therefore, y can’t be 7 if x is a positive integer.
Answer: B
Algebra, Exponents/Powers
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
GMAT/MBA Expert
-
Scott@TargetTestPrep
- GMAT Instructor
- Posts: 8086
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
If x = 1, y = 4^1 - 3 = 1.
If x = 2, y = 4^2 - 3 = 13.
If x = 3, y = 4^3 - 3 = 61.
If x = 4, y = 4^4 - 3 = 253.
We see that if x is an integer > 4, then y > 253. Therefore, y can’t be 7 if x is a positive integer.
Answer: B
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
