On a map, 90 miles is represented by 3 inches.
a measure of 1/2 inch on the map would represent miles.

Hi there!

We know that 1/2 inch = to 0.5
So we gonna use 0.5 instead of 1/2 because it would be easier to do the calculation part.

If
3 inch >>>>>>> 90 miles
0.5 inch >>>>>>> x ( x is the miles that we are looking for ) got it ?
Cross multiply
3x = 90*0.5
3x = 45
Divide both sides by 3
3x/3 = 45/3
x = 15 miles

Answer : A measure of 1/2 inch on the map would represent 15
miles.

I hope this answer help!

Have a great day ^^^!