Percentages SAT question

Choice B is correct. $10\%$ of a quantity means $\frac{10}{100}$ times the quantity. Therefore, $10\%$ of $470$ can be represented as $\frac{10}{100}(470)$, which is equivalent to $0.10(470)$, or $47$. Therefore, $10\%$ of $470$ is $47$.

Choice A is incorrect. This is $10\%$ of $370$, not $10\%$ of $470$.

Choice C is incorrect. This is $90\%$ of $470$, not $10\%$ of $470$.

Choice D is incorrect. This is $470-10$, not $10\%$ of $470$.