Two cars towards each other — one speed known by ratio: Two cars A and B start toward each other from points 88 km apart. Their speed ratio A:B is 5:6, and B’s speed is 90 km/h. After how many minutes will they meet?
Aptitude
Time and Distance
Difficulty: Easy
Choose an option
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A38 min
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B39 min
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C45 min
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D32 min
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E30 min
Answer
Correct Answer: 32 min
Explanation
Introduction / Context:Knowing a speed ratio and one absolute speed lets us compute the other speed, then use relative speed for meeting time.
Given Data / Assumptions:
- Distance = 88 km
- Speed ratio A:B = 5:6; B = 90 km/h ⇒ A = 75 km/h
Concept / Approach:Meeting time = distance / (sum of speeds).
Step-by-Step Solution:
Sum speed = 75 + 90 = 165 km/hTime = 88 / 165 h = 0.5333… h = 32 minVerification / Alternative check:Distances: A covers 75 * 0.5333… ≈ 40 km, B covers ≈ 48 km; sum 88 km.
Why Other Options Are Wrong:They correspond to incorrect speed sums or unit conversions.
Common Pitfalls:Forgetting to convert hours to minutes correctly.
Final Answer:32 min