Q. A man can row 15 km/hr downstream and 9 km/hr upstream, the speed of the boat in still water is :
Answer: 12 km/hr
Notes: Speed of boat in still water = $latex = \frac{1}{2}(Rate downstream + Rate upstream) = \frac{1}{2}(15+9)&s=1$ $latex = \frac{1}{2}\times 24 = 12 km/hr&s=1$ Hence option [C] is correct answer.

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