Motor boat covers a certain distance downstream in a river in 20 hours. It covers the same distance upstream in 30 hours. If the speed of the water is 12 km/hr, then the speed of the boat in still water is:

Let the distance be ‘D’ km According to the question, Downstream speed x + y = d/20 or d = 20 (x+y) .......... (i) Upstream speed x-y = d/30 or d = 30(x-y) ........... (ii) Comparing (i) & (ii) 20(x+y) = 30(x-y) 2(x+y) = 3(x-y) 2x + 2y = 3x - 3y x = 5y Hence, y = Speed of the current = 12 km/hour. Speed of boat, x = 5 × 12 = 60 km/hr

- If a man rows at the rate of 14 kmph in still water and his rate against the current is 5 kmph, then the man’s rate along the current is:
- A motorboat in still water travels at a speed of 36 km/hr. It goes 64 km upstream in 2 hours. The time taken by it to cover the same distance down the stream will be :
- Speed of current is equal to 25% of speed of boat in still water. If the boat takes 5 hours to cover 120 km in still water, then find the time taken by the boat to cover 108 km in upstream.
- A boat can travel 36 km downstream in 45 min. The ratio of the speed of the boat in still water to the speed of the stream is 5: 1. How much time will the boat take to cover 38 km upstream?
- The speed of a boat in still water is 32km/hr and the speed of the current is 8km/hr. It takes a total of 15hours to row to upstream from Point A to B and downstream from Point B to C. If the distance between A to C is two-fifth the distance between B and C then what is the distance between B and C? (Where BC < AB)
- Two boats A and B start towards each other from two places, 600 km apart. Speed of the boat A and B in still water are 23 km/h and 17 km/h respectively. If A and B proceeds against and with the stream, respectively then after how much time will they meet?
- A boat goes 8 km an hour in still water, but takes twice as much time in going the same distance against the current. The speed of the current (in km/hour) is :
- A boat takes 1/4th time in moving a certain distance downstream than upstream. The ratio of the speed of the boat in still water and that of current is?
- A motor boat goes downstream from point A to B ,which is 36 km away from point A, and then returns to A. If actual speed of the boat in still water is 7km/hour ,and the total upstream and downstream journey takes 21 hours .What must be the actual speed of boat for the journey from A to B to take exactly 108 minutes ?
- A man can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 5 hour to row to a place and come back, how far is the place?

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