Answer: The post office is 32 feet tall.
Step-by-step explanation:
We set up a proportion : 10ft/15ft = xft/48ft
In this equation "x" is the height of the post office. After setting up a proportion with the size of the buildings on the top (numerator) and the shadows of each building on the bottom (denominator) we cross multipy to get our equation to find x. We then divide both sides of the equation by 15 to get our answer.