Official Guide Explanation:
Problem Solving #43




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Solution and Metadata

Question: 43
Page: 158
Difficulty: 4 (Moderately Easy)
Category 1: Arithmetic > Fractions >

Explanation: The easiest way to do this may be to simply add the fractions. First, find a common denominator:

(7/8) + (1/9) = (63/72) + (8/72) = (71/72)

(71/72) is just a little bit below 1, so choice (B) is correct.

Alternatively, you could recognize that the difference between (7/8) and 1 is (1/8). Since (1/9) is a bit less than (1/8) , the sum of the two fractions must be a bit less than 1. Since, to answer the question, it doesn't matter what the exact sum of the fractions is, this method is equally valid, and might save a few seconds.

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