If x is a negative integer, which of the following expressions has the LEAST value?

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members
BTGmoderatorLU wrote:
Thu Apr 23, 2020 5:57 am
Source: GMAT Prep

If x is a negative integer, which of the following expressions has the LEAST value?

A. x^2 - 0.50
B. x^2 - 0.51
C. x^3 - 0.502
D. x^3 - 0.511
E. x^4 - 0.512

The OA is D
Given that x is a negative integer, the values of x with even exponents will have positive values, while the values of x with odd exponents will have negative values.

Since negative values are smaller than the positive values, we must look for the negative value whose absolute value is largest.

Since Option A, B and E have x with even exponents, we can leave them.

The correct answer would be between Option C and D.

Note that in these options, x^3 is common, so we can leave x^3; the decider would be –0.502 and –0.511. Since –0.502 > –0.511, the correct answer is Option D.

The correct answer: D

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: Manhattan Review Chennai | Hyderabad | GRE Prep New Delhi | Tarnaka GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members
BTGmoderatorLU wrote:
Thu Apr 23, 2020 5:57 am
Source: GMAT Prep

If x is a negative integer, which of the following expressions has the LEAST value?

A. x^2 - 0.50
B. x^2 - 0.51
C. x^3 - 0.502
D. x^3 - 0.511
E. x^4 - 0.512

The OA is D
Since x^3 is negative and both x^2 and x^4 are positive, we can narrow down the answer choices to C and D. Since 0.511 is the largest decimal being subtracted from x^3, then x^3 - 0.511, will produce the least value.

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage