If d is a positive integer, is d^1/2 greater than 15?
(1) d is divisible by 25.
(2) d is divisible by 40.
Q/a -e
(1) d is divisible by 25.
(2) d is divisible by 40.
Q/a -e
Target question: Is d^(1/2) greater than 15?Ankitaverma wrote:If d is a positive integer, is d^(1/2) greater than 15?
(1) d is divisible by 25.
(2) d is divisible by 40.
If x > 0, then x^(1/2) = √x, so we can use this to rephrase the target question...
REPHRASED target question: Is √d > 15?
Also, since √225 = 15, √d will be greater than 15 only if d > 225
So, we can rephrase the target question as...
RE-REPHRASED target question: Is d > 225?
Okay, now let's jump straight to . . .
Statements 1 and 2 combined
We're looking for a number that is divisible by 25 AND is divisible by 40. There are several values of d satisfy these conditions. Here are two:
Case a: d = 200, in which case d < 225
Case b: d = 400, in which case d > 225
Since we cannot answer the RE-REPHRASED target question with certainty, the combined statements are NOT SUFFICIENT
Answer = E
Cheers,
Brent
