Quantitative Aptitude • Time, Speed & WorkMedium
A boat moves at 13 km/h in still water and the stream flows at 3 km/h. How long will the boat take to go 80 km downstream and come back?
A. 5 hours
B. 13 hours✓ Correct Answer
C. 12.31 hours
D. 8 hours
💡 Solution & Explanation
Downstream the stream helps: 13 + 3 = 16 km/h, so going takes 80 ÷ 16 = 5 hours. Upstream the stream works against it: 13 − 3 = 10 km/h, so coming back takes 80 ÷ 10 = 8 hours. Total time = 13 hours.
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