Question

a door - stopper is a triangle with a height increase of 2 inches for every 5 - inch increase in the length of the horizontal base. the top corner of the door - stopper fits exactly in the 3 - inch space between the bottom of a door and the floor. what is the length, in inches, of the base of the door - stopper? a 1.2 b 2.5 c 5.0 d 7.5

Explanation:

Step1: Set up proportion

Let $x$ be the length of the base. The ratio of height - to - base is $\frac{2}{5}$. Since the height is 3 inches, we set up the proportion $\frac{2}{5}=\frac{3}{x}$.

Step2: Cross - multiply

Cross - multiplying gives us $2x = 3\times5$.

Step3: Solve for $x$

$2x=15$, so $x=\frac{15}{2}=7.5$.

Answer:

D. 7.5