GMAT Practice Question: Terry needs to purchase some pipe for a plumbing job that requires pipes with lengths of 1 ft 4...
Question
Terry needs to purchase some pipe for a plumbing job that requires pipes with lengths of 1 ft 4 in, 2 ft 8 in, 3 ft 4 in, 3 ft 8 in, 4 ft 8 in, 5 ft 8 in, and 9 ft 4 in . The store from which Terry will purchase the pipe sells pipe only in 10-ft lengths. If each 10-ft length can be cut into shorter pieces, what is the minimum number of 10-ft pipe lengths that Terry needs to purchase for the plumbing job? (Note: 1 ft=12 in )
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Topics: conversions, word problems
Solution
Step 1
We convert each of the listed required lengths from the question ("1 ft 4 in", "2 ft 8 in", "3 ft 4 in", "3 ft 8 in", "4 ft 8 in", "5 ft 8 in", "9 ft 4 in") into inches using the relation 1 ft=12 in.
1 ft 4 in = 1 12 + 4 = 16 in 2 ft 8 in = 2 12 + 8 = 32 in 3 ft 4 in = 3 12 + 4 = 40 in 3 ft 8 in = 3 12 + 8 = 44 in 4 ft 8 in = 4 12 + 8 = 56 in 5 ft 8 in = 5 12 + 8 = 68 in 9 ft 4 in = 9 12 + 4 = 112 in
Step 2
We sum all these lengths in inches to find the total required pipe length.
16 + 32 + 40 + 44 + 56 + 68 + 112 = 368 in
Step 3
We convert the available length sold by the store ("10-ft") into inches using 1 ft=12 in.
10 ft = 10 12 = 120 in
Step 4
We divide the total required length by the available length per pipe to see how many full 10-ft pipes we can use, and to find any leftover.
368/120 = 240/120 + 120/120 + 8/120 = 2 + 1 + 8/120 = 3 remainder 8
Step 5
Since there is a remainder of 8 inches after using 3 full pipes, we need one more 10-ft pipe, for a total of 4 pipes.
3 + 1 = 4
Answer
4
