Question
Download Solution PDFA boat can travel 20 km upstream in 5 hours and 30 km downstream in 3 hours. Find the speed of the boat in still water (in km/hr).
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Distance upstream = 20 km
Time upstream = 5 hours
Distance downstream = 30 km
Time downstream = 3 hours
Formula used:
Speed upstream (u) = Distance upstream ÷ Time upstream
Speed downstream (d) = Distance downstream ÷ Time downstream
Speed of boat in still water = (Speed upstream + Speed downstream) ÷ 2
Calculations:
Speed upstream (u) = 20 ÷ 5
⇒ u = 4 km/hr
Speed downstream (d) = 30 ÷ 3
⇒ d = 10 km/hr
Speed of boat in still water = (u + d) ÷ 2
⇒ Speed of boat in still water = (4 + 10) ÷ 2
⇒ Speed of boat in still water = 14 ÷ 2
⇒ Speed of boat in still water = 7 km/hr
∴ The correct answer is option (1).
Last updated on Apr 24, 2025
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