If b equals 20% of b, then which one of the following equals 30% of c?
A
0.0006% of a
B
0.006% of a
C
0.06% of a
D
0.6% of a
Correct Answer: 0.6% of a
30% of c = ·30×c = ·30×·20b = ·30×·20×·10a = ·006a = ·6% of a