If x is a positive integer, is x^1/2 < 2.5x - 5 ?
1. x < 3
2. x is a prime number
OA is A, I went for C
Here's how I approached the problem.
I didn't like the square root on the LHS so I restated the question as "Is x< (2.5x - 5)^2". Is there anything wrong with my operation to square both sides of the inequality?
Considering the statements:
[spoiler]STMT 2: Considering prime number (2), I get "Is 2<0" - NO. Considering prime number (3), I get "Is 3<6.25" - YES; therefore, 2 is INSUFFICIENT - ELIMINATE B
STMT 1: The values of x are 1 and 2. Considering (1), I get "Is 1<6.25" - YES. Considering (2) from above, the answer is NO, therefore 1 is INSUFFICIENT - ELIMINATE A
Combining both statements, we are left with only prime number (2), therefore we have a NO, hence C is SUFFICIENT.[/spoiler] Alas I'm wrong
Someone please provide some illumination!!
1. x < 3
2. x is a prime number
OA is A, I went for C
Here's how I approached the problem.
I didn't like the square root on the LHS so I restated the question as "Is x< (2.5x - 5)^2". Is there anything wrong with my operation to square both sides of the inequality?
Considering the statements:
[spoiler]STMT 2: Considering prime number (2), I get "Is 2<0" - NO. Considering prime number (3), I get "Is 3<6.25" - YES; therefore, 2 is INSUFFICIENT - ELIMINATE B
STMT 1: The values of x are 1 and 2. Considering (1), I get "Is 1<6.25" - YES. Considering (2) from above, the answer is NO, therefore 1 is INSUFFICIENT - ELIMINATE A
Combining both statements, we are left with only prime number (2), therefore we have a NO, hence C is SUFFICIENT.[/spoiler] Alas I'm wrong
Someone please provide some illumination!!
