How do you figure 12 is 30% of what number

Ineed with this. the figure is made up of a square and a rectangle. find the area of the shaded region.

List the sides of δrst in ascending order (shortest to longest) if: m∠r =x+28°, m∠s = 2x+16°, and m∠t = x+12

The ratios of boys to girls on a soccer league is 2: 5. if there are 28 boys, how many girls are playing soccer? extra points! will mark as brainiest asap