The supermarket has 28 aisles. 75% are empty, without any shoppers. How many empty aisles are there in the supermarket?

21

28/75%=28

there ya go

i use my brain for prombles like this maybe you could try it

step-by-step explanation:

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.