from Nova:
Example 2:
Column A
The number of distinct
prime factors of x
Column B
The number of distinct
prime factors of 4x
We expect the number of prime factors of 4
x to be larger than the number of prime factors of x. But that is
the eye-catcher. Now, the number of prime factors of 4x cannot be less than the number of prime factors of
x since 4x contains all the factors of x. So the answer must be that either they are equal or there is not enough information. In fact, there is not enough information, as can be verified by plugging in the numbers
x = 2 and then x = 3.
How is it possible that A and B are equal?