AbeNeedsAnswers wrote:Is the integer x a 3-digit integer?
(1) x is the square of an integer.
(2) 90 < x < 150
Target question: Is the integer x a 3-digit integer?
Statement 1: x is the square of an integer.
Let's TEST some values.
There are several values of x that satisfy statement 1. Here are two:
Case a: x = 10² = 100. In this case, the answer to the target question is
YES, x IS a 3-digit integer
Case b: x = 9² = 81. In this case, the answer to the target question is
NO, x is NOT a 3-digit integer
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: 90 < x < 150
TEST some cases.
Case a: x = 100. In this case, the answer to the target question is
YES, x IS a 3-digit integer
Case b: x = 91. In this case, the answer to the target question is
NO, x is NOT a 3-digit integer
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
There are THREE values of x that satisfy BOTH statements: x = 100, x = 121 and x = 144
In all three cases, the answer to the target question is the same:
YES, x IS a 3-digit integer
Since we can answer the
target question with certainty, the combined statements are SUFFICIENT
Answer: C
Cheers,
Brent
