Answer
F
Work Step by Step
$a=percentage \times base$ (formula for finding a base)
Base 1: $3000=.15 \times b$ (Divide 3000 by .15)
b=20,000
Base 2: $3600=.15 \times b$ (Divide 3600 by .15)
b=24,000
$24,000-20,000=4000$
There is a difference of 4000.
