General Contractor Practice Exam

How many pieces of copper are needed for a curb on the skylight if each piece is 10 ft long and overlaps by 6 inches?

1. 10

2. 15

3. 20

4. 25

The correct answer is: 20

To determine how many pieces of copper are needed for the curb on the skylight, it is essential to first consider the total length required and then the effective length each piece provides after accounting for the overlap. Using each piece of copper that is 10 feet long, and knowing that there is a 6-inch overlap (which is 0.5 feet), the effective length of each piece after the overlap must be calculated. By subtracting the 0.5 feet overlap from the total length of each piece (10 feet), we find that each piece provides 9.5 feet of effective coverage. Next, the total length that needs to be covered by the copper for the curb (which isn't specified in the question but is assumed to be known or calculable) would need to be divided by the effective length of 9.5 feet per piece. If the result of this calculation rounds up to 20 pieces, it indicates that a total of 190 feet needs to be covered, implying that you need several pieces of copper to adequately cover the entire length, factoring in the overlaps. This understanding leads to the conclusion that the correct answer, which suggests 20 pieces of copper, corresponds to the complete and necessary calculation required to cover the