A man rows a certain distance downstream in 5 hours and back to the same point in 8 hours. If the speed of the stream is 4.5 km/hr then what is the speed of the man in still water?

Let the speed of the man in still water be x km/hr. Downstream speed = (x+ 4.5) km/hr. Upstream speed = (x- 4.5) km/hr. (x+ 4.5) × 5 = (x- 4.5) × 8 5 x + 22.5 = 8 x - 36 3 x = 58.5 ∴ x = 19.5 km/hr.

- The speed of a boat in still water is 10 kmph. It covers a distance of 60 km downstream in 5 hrs. The speed (in kmph) of the stream is
- 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 makes a journey from point P to point Q and return back in 6 hr 40 min. One way it travels with the stream and on the return it travel against the stream. Prdouct of speed in downstream and upstream is 216. If the speed of the stream increase by 2 km/hr, the return journey takes 7 hr 12 min. What is the speed of the boat in still water? The distance between P and Q is 48 km.
- Two boats X and Y start towards each other from two places, 119 km apart. Speed of the boat X and Y in still water are 7 km/hr and 10 km/hr respectively. If X proceeds down and Y up the stream, they will meet after.
- The speed of a boat in still water is 6 km/hr and speed of current is 3 km/hr. If time taken to cover a certain distance upstream is 21 hours, then how long will the boat take to cover the same distance downstream?
- A man can go on a motor boat with a speed of 25 km/hour in still water to a certain upstream point and come back to the starting point in a river which flows at a speed of 15km/hour. Find the average speed of motor boat for total journey?
- A man can row 13 km/hr in still water. When the river is running at 5 km/hr, it takes him 6.5 hours to row to a place and back. How far is the place?
- The speed of the boat in still water is 10 km/h and the speed of the stream is 6 km/h. A boat goes 48 km downstream with its usual speed but at the time of returning the speed of the boat in still water is tripled. Find the total time taken by boat to cover the whole distance.
- Boat ‘A’ can cover 120 km in still water in 10 hours. In still water, if the ratio of the speed of boat ‘A’ to that of ‘B’ is 4:5 and the speed of stream is 2 km/hr then find the time taken by boat ‘B’ to cover the 170 km in downstream.
- Ratio of distance covered by boat in upstream to downstream is 4:3. Time taken in downstream and upstream is 2hr and 4 hr respectively. If speed of boat in still water is 15 km/hr then find speed of stream.

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