Official Guide Explanation:
Problem Solving #225




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Solution and Metadata

Question: 225
Page: 184
Difficulty: 6 (Moderately Difficult)
Category 1: Arithmetic > Fractions >
Category 2: Word Problems > Other >

Explanation: It may be easier to think of this pipe as 12 yards in length, since then the markings in fourths and thirds will have integer values instead of fractional ones. The markings in fourths will come at 3, 6, and 9 yards. The markings in thirds will be at 4 and 8 yards. Altogether, there will be markings at 3, 4, 6, 8, and 9 yards. So, in the 12 yard pipe, there are pieces between markings of 3, 1, 2, 2, 1, and 3 yards. We only need to look at one of each length, and divide them by 12 to adjust back to a 1 yard pipe. Those are (3/12), (1/12), and (2/12), or, reduced: (1/4), (1/12), and (1/6), choice (D).

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