Question

Question :- Ram can row downstream 20 km in 2 hours and upstream 4 km 2 hours. Find his speed of rowing in still water and speed of current.​

Answer 1

Answer:

(i) Ritu can row downstream 20 km in 2 hours, and upstream 4 km in 2 hours. Hence, Ritu's speed of rowing in still water is 6 km/h and the speed of the current is 4 km/h.

Answer 2

(i) Let Ram’s speed of rowing in still water and the speed of the stream be x km/h and y km/h respectively.

Ram’s speed of rowing;

Upstream = ( x - y ) km/h

Downstream = ( x + y ) km/h

According to question,

Ram can row downstream 20 km in 2 hours,

2( x + y) = 20 [Since, Distance = Speed × Time]

x + y = 10 ....(1)

Ram can row upstream 4 km in 2 hours,

2( x - y) = 4

x - y = 2 ....(2)

Adding equation (1) and (2), we obtain

x + y + x - y = 10 + 2

2x = 12

x = 6

Putting x = 6 in equation (1), we obtain

6 + y = 10

y = 4

Hence, Ram’s speed of rowing in still water is 6 km/h and the speed of the stream is 4 km/h.

hope it was helpful

army

Best Regards

Naisha