A boat's speed in still water is 12 km/h and the stream flows at 3 km/h. How long does it take to go 48 km downstream and return?
Answer and explanation
Correct answer: D. 8.53 hours
- Step 1: Downstream speed = 12 + 3 = 15 km/h; upstream speed = 12 - 3 = 9 km/h.
- Step 2: Time = 48/15 + 48/9 = 8.53 hours.
Answer
8.53 hours.
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