Answer:
E) 15/64
Explanation:
To compare the numbers, it works best to express them all using a common denominator. One possibility is 1600, another is 1,000,000.
9/40 = 360/1600
5/16 = 500/1600
9/32 = 450/1600
0.28 = 448/1600
15/64 = 375/1600
The number we're comparing to is 0.25 = 400/1600, so we want to find the closest number to 400 in the set ...
... {360, 500, 450, 448, 375}.
The magnitude of the differences of these numbers from 400 is ...
... {40, 100, 50, 48, 25}.
Clearly, the last number, 15/64 = 375/1600 has the smallest difference from 0.25.