Question

Swati can row her boat at a speed of 5 km/h in still water. If it takes her 1 hour more to row the boat 5.25 km upstream then to return downstream, find the speed of the stream.

Answer 1

Speed of boat in still water = 5 km/h

Let speed of stream be 'x' km/h.

Speed of boat in upstream = (5 - x) km/h

Speed of boat in downstream = (5 + x) km/h

Distance travelled by boat in upstream = Distance travelled by boat in downstream = 5.25 km

ATQ:-

=> 5.25(1/5-x - 1/5+x) = 1

=> 5.25 ( 2x/25 - x^2) = 1

=> 10.5x = 25 - x^2

=> x^2 +10.5x - 25 = 0

=> (x+12.5)(x-2) = 0

=> x = 2 or x = -12.5

x can't be -12.5 as speed can't be negative

Therefore, Speed of stream is 2 km/h.

Hope this helps!

Answer 2

Answer is in the attachment