$10 \%$ of 200 is equal to $20 \%$ of
(A) 40
(B) 50
(C) 100
(D) 400
(E) 800
Since $10 \%$ of 200 is $\frac{10}{100} \times 200=10 \times 2=20$, and $20 \%$ of 100 is $\frac{20}{100} \times 100=20$, then $10 \%$ of 200 is equal to $20 \%$ of 100 .

ANSWER: $(\mathrm{C})$