What is the duration of an asphalt shingle job of 120 squares if a three-person crew can install 15 squares per day?

To determine the duration of an asphalt shingle job of 120 squares, you first need to calculate how many squares are installed per day by the crew. Since the three-person crew can install 15 squares in a day, you can find the total number of days required to complete the job by dividing the total number of squares by the daily installation rate.

Calculating this gives:

Total squares = 120
Installation rate per day = 15 squares/day

Now, divide the total number of squares by the daily installation rate:

120 squares ÷ 15 squares/day = 8 days

Thus, it will take the crew 8 days to complete the asphalt shingle job for 120 squares.