Question

the dimensions of a blackboard are $\frac{9}{10}$ of a meter by $\frac{7}{10}$ of a meter. in a drawing of the blackboard shown, $\frac{1}{2}$ of an inch represents 2 meters.
image of a rectangle labeled with $\frac{7}{40}$ in (height) and $\frac{9}{40}$ in (width), note: figure not drawn to scale
what is the unit rate of area in square meters of the blackboard per square inch of area in the drawing?
a. 4 square meters per square inch
b. 16 square meters per square inch
c. 64 square meters per square inch
d. 32 square meters per square inch

Explanation:

Step1: Find length scale factor

We know $\frac{1}{2}$ inch = 2 meters, so 1 inch = $2\times2=4$ meters.

Step2: Find area scale factor

The area scale factor is the square of length scale factor: $4^2=16$ square meters per square inch.

Answer:

B. 16 square meters per square inch