The first thing you should do in this case is to take out the area of the patio and the area covered by each brick.
Patio area = (15) * (20) = 300 ft ^ 2
Area brick = (1) * (1) = 1ft ^ 2
Then, to get the number of bricks we have:
n = (Patio area) / (Area brick)
n = (300) / (1)
n = 300
Therefore, 300 bricks are needed. This means that the total cost is
total cost = (2) * (300) = 600 $
answer
Sam will spend if he buys exactly enough tiles to cover his patio $ 600
