Calculate the number of hangers needed to support 275 feet of pipe with a hanger placed every 8 feet.

To determine the number of hangers needed to support 275 feet of pipe with a hanger installed every 8 feet, you start by dividing the total length of the pipe by the spacing distance of the hangers.

First, divide 275 feet by 8 feet:

275 feet ÷ 8 feet = 34.375.

Since you cannot have a fraction of a hanger, you need to round up to account for the final hanger at the end of the pipe. This means you need a total of 35 hangers, but because there will be a hanger needed at the starting point (0 feet) as well, you must add one more hanger.

Thus, you would need:

34 hangers for the 8-foot intervals plus 1 more at the end, giving you a total of 35 hangers.

The correct answer should therefore be 35 hangers. It seems there might be a mistake in the answer choice presented as D, which states 40 hangers, as that number does not align with the calculated requirement based on the given spacing and total pipe length.