The sum 1 ft 3-3/4 in plus 2 ft 1-1/16 in plus 5 ft 10-7/8 in equals which value?

• A. 9 ft 2-11/16 in
• B. 9 ft 3-1/16 in
• C. 9 ft 3-11/16 in
• D. 9 ft 4-7/8 in

Answer: (C)

You add mixed units by turning everything into a single unit, then convert back. Convert each term to inches: 1 ft 3-3/4 in is 12 in plus 3.75 in = 15.75 in. 2 ft 1-1/16 in is 24 in plus 1.0625 in = 25.0625 in. 5 ft 10-7/8 in is 60 in plus 10.875 in = 70.875 in. Sum these: 15.75 + 25.0625 + 70.875 = 111.6875 inches.

Now convert back to feet and inches. 111.6875 inches equals 9 feet (108 inches) with a remainder of 3.6875 inches. Turn the remainder into a fraction: 0.6875 equals 11/16, so the remainder is 3-11/16 inches. Therefore the total is 9 ft 3-11/16 in.