taneja.niks wrote:p and q are different two-digit prime numbers with the same digits, but in reversed order. What is the value of the larger of p and q?
(1) p + q = 110
(2) p - q = 36
what shall be he right answer??
It might be useful to list the possibilities before examining the statement.
Given that p and q are both 2-digit prime numbers with the the digits reversed, there are only 3 pairs of numbers to consider:
13 & 31, 17 & 71, 37 & 73
Listing possible pairs shouldn't take long because you can skip a LOT of numbers. For example, numbers beginning with 2 (21, 22, 23, etc) can be ignored because the reversed number will end with 2, which means it cannot be prime)
Statement 1
p + q = 110
This tells us that the number pair must be 37 and 73.
We don't know which number is equal to p and which number is equal to q, but it doesn't matter.
The question asks for the value of the larger number, so that answer is 73
Since we can answer the target question with certainty, statement 1 is sufficient
Statement 2
p - q = 36
Of our 3 possible pairs of numbers, only 37 & 73 meet this condition.
The larger number is 73, so statement 2 is sufficient
Answer =
D
