Solutions
Get detailed explanations to advanced GMAT questions.
Question
If k is negative, which of the following must also be negative?
Option A:
(-k)^2
Option B:
(-1)k
Option C:
1-k
Option D:
k+1
Option E:
k-1
Difficulty Level
EasySolution
Option E is the correct answer.
Option Analysis
For MUST-BE questions, Plugging- In
Given k is negative, so let’s take k = -1.
Substitute in the answer choices.
A. (-k)^2 –> (-(-1))^2 = 1 – Positive – So eliminate.
B. (-1)k –> (-1)k = (-1)(-1) = 1 – Positive – So eliminate.
C. 1-k –> 1-k = 1-(-1) -2– Positive – So eliminate.
D. k+1 –> k+1 = -1+1 = 0 –Neither Positive or Negative – So eliminate.
E. k-1 –> k-1 = -1-1 = -2—Negative-So this is the answer.
Related Questions
- If Sn is the sum of the first n terms of a certain sequence and if Sn = n(n+1) for all positive integers…
- If 0 < x < 2, which of the following must be greatest?
- If x^2 = y^2, is true that x>0?
- 3 teaspoons = 1 tablespoon, 4 tablespoons = 1/4 cup. According to the information above, how many teaspoons are equal to 3/8 cup?
- Which of the following is equivalent to ((a+b)/2)+ ((a-b)/3)?