Gmat_mission wrote: ↑

Sun Aug 08, 2021 10:25 am

While flying across the country, did Karen ever exceed 650 miles per hour?

(1) Karen flew 3,000 miles.
(2) Karen flew for 5 hours.

Answer: E

Source: Veritas Prep

NOTE: There's nothing here to suggest that Karen's speed was constant. Sure, she MIGHT have traveled at a constant speed, or her speed may have varied throughout the trip.

Target question: Did Karen's speed ever exceed 650 miles per hour?

Statement 1: Karen flew 3,000 miles
No information about Karen's travel TIME so statement 1 is NOT SUFFICIENT
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 1 hour flying 3000 miles, in which case her speed was 3000 miles per hour. So, Karen's speed DID exceed 650 miles per hour
Case b: flying at a constant speed, Karen spent 10 hours flying 3000 miles, in which case her speed was 300 miles per hour. So, Karen's speed did NOT exceed 650 miles per hour
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: Karen flew for 5 hours
No information about the DISTANCE Karen traveled. So, statement 2 is NOT SUFFICIENT
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 5 hours flying 5000 miles, in which case her speed was 1000 miles per hour. So, Karen's speed DID exceed 650 miles per hour
Case b: flying at a constant speed, Karen spent 5 hours flying 5 miles, in which case her speed was 1 mile per hour. So, Karen's speed did NOT exceed 650 miles per hour
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Consider these two possible scenarios that yield conflicting answers to the target question:
Case a: flying at a constant speed, Karen spent 5 hours flying 3000 miles, in which case her speed was 600 miles per hour. So, Karen's speed did NOT exceed 650 miles per hour
Case b: Karen flew 2000 miles (at a constant speed) for 1 hour, and then spent 4 hours flying the remaining 1000 miles. So, Karen's speed DID exceed 650 miles per hour
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E