8
Answer: BSet 10: Systems of Equations
Explanation
Two hikers start from the same trailhead walking in opposite directions. Hiker A walks at 3 mph, Hiker B at 4 mph. After how many hours will they be 10.5 miles apart?
A.
1 hour
B.✓ Correct
1.5 hours
C.
2 hours
D.
2.5 hours
Detailed Explanation
Choice B is correct. Choice B is the correct answer. Opposite directions → add speeds. Let = time in hours. Combined rate: mph Equation: $$$7t = 10.5t = 1.5$$ Solution: 1.5 hours Verification: In 1.5 hours: 3(1.5) + 4(1.5) = 4.5 + 6 = 10.5$ miles ✓ Strategic Tip: When moving apart, add speeds to find separation rate. Other choices fail verification.
Key Steps:
•
The correct answer is 1.5 hours
Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.
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