Official Guide Explanation:
Problem Solving #154




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Solution and Metadata

Question: 154
Page: 174
Difficulty: 5 (Moderate)
Category 1: Word Problems > Measurement Problems >
Category 2: Word Problems > Rate Problems > Speed
Category 3: Arithmetic > Ratio and Proportion >

Explanation: The question tells you how long it takes for the pool to fill (3/5) of the way, and it wants to know how long it will take to fill the remaining (2/5). This is a ratio, so set it up like one. ((amount)/(time)) = (((3/5))/8) = (((2/5))/(x)). Cross - multiply: (3/5)(x) = (2/5)(8), or 3x = 16, or x = (16/3) = 5(1/3)= 5 hours, 20 minutes, choice (B).

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