The speed of current is 9 km/h. What will be the respective downstream speed and upstream speed of a boy rowing a boat, if one seventh of the distance covered going downstream in a certain time is equal to the distance covered going upstream in the same time?

Let the speed of boy in still water be X km/h. And the speed of current = 9 km/h Downstream speed = (X + 9) km/h Upstream speed = (X – 9) km/h Let time be ‘t’ hours. ⇒ [(X + 9) t]/7 = (X – 9) t ⇒ X + 9 = 7X – 63 ⇒ X = 12 km/h Downstream speed = 12 + 9 = 21 km/h Upstream speed = 12 – 9 = 3 km/h

- A man can row upstream at 18 km/hr and downstream at 24 km/hr. Find the man’s rate in still water and the rate of the current.
- Motor boat covers a certain distance downstream in 5 hours. It covers the same distance upstream in 7(1/2) hour. If the speed of the water is 4.5 km/hr, then the speed of the boat in still water is:
- Find the total distance covered by boat in each upstream and downstream in 6 hours if the speed of boat in still water and speed of current is 15 km/h and 5 km/h respectively?
- Find the total distance covered by boat in each upstream and downstream in 5 hours if the speed of boat in still water and speed of current is 25 km/h and 6 km/h respectively?
- A boat takes 7 hours to cover 294 km upstream and 9 hours to cover 486 km downstream. Find the time taken by the boat to cover 720 km upstream and 616 km downstream if speed of boat in still water is increased by 4 km/h and speed of stream is decreased by 2 km/h.
- Two boats X and Y start towards each other from two places, 155 km apart. Speed of the boat X and Y in still water are 14 km/hr and 17 km/hr respectively. If X proceeds down and Y up the stream, they will meet after.
- 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 ?
- The speed of a boat in still water is 8 km/hr and speed of current is 3 km/hr. If time taken to cover a certain distance upstream is 11 hours, then how long will the boat take to cover the same distance downstream?
- Nobita can row from a point A against a current for 30 minutes and then come back in favour of the current for the next 30 minutes and comes to the point B. If the distance of AB is 2`2/5` km, then find the speed of the current (in km/hr)?
- 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 :

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