How many integers between 10 and 50 (inclusive) meet the following conditions? 1. The sum of the digits is odd. 2. The number is a perfect square.
a) 3
b) 4
c) 5
d) 6

Answer :

LammettHash

There are only a handful of perfect squares in the given range: 16, 25, 36, and 49

The sum of their digits wil be odd if one digit is odd and the other is even, which is the case for 16, 25, and 49. So the answer is A.

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