Question

A person can row down a stream at 6 km per hour and up the same stream at 3 km per

hour. His rate in still water is

a) 9 km/hr b) 4.5 km/hr c) 1.5 km/hr d) 1.0 km/hr

Answer 1

Let be the speed of boat is x
And the speed of stream is y
1sr case, downstream

X+y = 6................(1)

2nd, upstream

X-y = 3...............(2)

Comparing both eq

X+y =6
X-y =3
—————
2x = 9
X = 9/2

[ X= 4.5 km/h ] ans