Ok, let's assume the following variables!

L= (The distance of the back wall = the length of the patio) = 32 feet (this is told to us)

W = how far the patio extends from the wall (what we're trying to find)

A = The total area of the patio tiles

Clearly, if the patio tiles are 1ft by 1ft big and there's 256 of these, then the total area (A) will be 256 feet squared, correct?

(1 patio tile = 1ft squared. Hence, 256 = 256 ft squared)

Therefore, A = 256 feet squared.

By using the Area formula for a rectangle (which happens to contain all of our variables) we can solve the problem:

A=L*W

256 = 32 * W

Solving for W:

256/32 = W

Therefore, W (what we're trying to find) = 8 feet