A boat covers 14 km upstream in 56 minutes (stream speed 2 km/h). Find the boat’s still-water speed.
Aptitude
Boats and Streams
Difficulty: Medium
Choose an option
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A6 km/hr
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B15 km/hr
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C14 km/hr
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D17 km/hr
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E—
Answer
Correct Answer: 17 km/hr
Explanation
Introduction / Context:Convert minutes to hours, deduce upstream speed, then add the known stream speed to get still-water speed.
Step-by-Step Solution:
Time = 56 min = 56/60 h.Upstream speed u = distance/time = 14 ÷ (56/60) = 14 × 60/56 = 15 km/h.With stream s = 2, still-water b = u + s = 15 + 2 = 17 km/hr.