Answer:
The maximum number of hand-painted tiles that Greg can use to keep the total cost under $ 200 is 19.
Step-by-step explanation:
Since Greg is installing a tile floor in a room that is 10 feet long by 15 feet wide, and he will use 1-foot square tiles, and he has two different types of tile: plain and hand-painted, and plain tiles cost $ 0.79 per tile, while hand-painted tiles cost $ 5.00 per tile, to determine what is the maximum number of hand-painted tiles that Greg can use to keep the total cost under $ 200, the following calculation must be performed:
10 x 15 = 150
150 x 0.79 + 0 x 5 = 118.5
130 x 0.79 + 20 x 5 = 202.7
131 x 0.79 + 19 x 5 = 198.49
Therefore, the maximum number of hand-painted tiles that Greg can use to keep the total cost under $ 200 is 19.