If f (x) = 3x, g (x) = x-3, and h (x) = square root of x, find (fogoh) (25)

(f o g o h) (x) = f { g [ h (x) ] }

Which means: apply first function h, then apply function g to the result, and finally apply function f to the new result.

h (25) = √25 = 5

g (5) = 5 - 3 = 2

f (2) = 3 (2) = 6.

Answer: 6