Verified Answer :

42.5% of what = 20.57

42.5% of x = 20.57

(42.5/100)x = 20.57

42.5x / 100 = 20.57

x = 20.57
100 / 42.5

x = 48.4

Therefore 42.5% of 48.4 is 20.57.

The answer would be 48.4