If 3:9 is to 4:16, then 5:25 is to?

Answer: A. 36
The relationship is that the second number is the square of the first number multiplied by 3. 3*3=9, 4*4=16, 5*5=25, so the answer is 36 (6*6).
Posted in:  Number Analogy -  Analogy -  Verbal Reasoning