Answer:
160 tiles.
Explanation:
First let's make an equation.
Each tile costs $4, let's make t=number of tiles.
+$15.82, and the total cost being $655.82
So ideally our equation would look like
4t+15.82=655.82
Now solve.
First, subtract 15.82 on both sides.
4t=640
Second, divide 4 on both sides to make the variable t by itself.
t=160
So, the contractor purchased 160 tiles.