Find the shortest length of 1/2 inch conduit from which the following pieces can be cut: 7 7/8 inches, 3 1/4 inches, 6 1/2 inches, 12 1/8 inches and 24 3/16 inches. Allow 1/16 inch for each saw cut.

• A. 54 3/16 inches
• B. 54 1/8 inches
• C. 53 7/16 inches
• D. 54 1/4 inches

Answer: (A)

The idea is you’re cutting five pieces from one piece of conduit, so you need four saw cuts. Each cut takes up 1/16 inch of length, giving a total kerf of 4 × 1/16 = 1/4 inch.

Add up all the piece lengths exactly:

7 7/8 = 63/8

3 1/4 = 26/8

6 1/2 = 52/8

12 1/8 = 97/8

24 3/16 = 387/16 (convert to sixteenths to sum cleanly)

Sum in sixteenths: 126/16 + 52/16 + 104/16 + 194/16 + 387/16 = 863/16 = 53 15/16 inches.

Add the kerf: 53 15/16 + 1/4 = 53 15/16 + 4/16 = 867/16 = 54 3/16 inches.

So the shortest stock length that fits all pieces with the saw-cut allowances is 54 3/16 inches.