Given: Q is an integer between 10 and 100AAPL wrote: If Q is an integer between 10 and 100, what is the value of Q?
1) One of Q's digits is 3 more than the other, and the sum of its digits is 9.
2) Q < 50.
Target question: What is the value of Q? Okay great what a great idea
Statement 1: One of Q's digits is 3 more than the other, and the sum of its digits is 9.
There are exactly two 2-digit numbers that satisfy statement one: Q = 36 and Q = 63
Statement 1 is NOT SUFFICIENT
Statement 2: Q < 50
This means Q could equal 11 or 12 or 13 or 14 or . . .
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
Statement 1 tells us that EITHER Q = 36 OR Q = 63
Statement 2 tells us that Q < 50
So it must be the case that Q = 36
Since we can answer the target question with certainty, the combined statements are SUFFICIENT
Answer: C
Cheers,
Brent
