SAT Question 77cf4fa6: Percentages answer and explanation with Desmos solution

It's given that there are $170$ blocks in a container, and of these blocks, $10\%$ are green. Since $10\%$ can be rewritten as $\frac{10}{100}$, or $0.1$, the number of green blocks in the container is $0.1\left(170\right)$, or $17$.