Official Guide Explanation:
Data Sufficiency #D38




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Solution and Metadata

Question: D38
Page: 25
Difficulty: 5 (Moderate)
Category 1: Algebra > Inequalities > other
Category 2: Word Problems > Rate Problems > Speed

Explanation: If Paula's speed were exactly 70 km per hour, she could travel as many as 210 miles in 3 hours. Since we know her speed was greater than 70kph, it would take her less than 3 hours to travel 210 or fewer km. It's possible she could drive further than 210 miles in less than 3 hours, but since we don't know her exactly speed, we don't know the exact distance she could travel in that time.

Statement (1) is insufficient. If the distance is greater than 200 km, it could be completed in under 3 hours--if the distance is less than 210 km. If it's greater than 210 km, we don't know whether she could drive that far in under 3 hours.

Statement (2) is sufficient. We know she can drive as much as 210 km in under 3 hours, so it follows that she could drive less than 205 km in under 3 hours. Choice (B) is correct.

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