Question

A man can row his boat with the stream at 6 km/h and against the stream in 4 km/h. The man's rate is?
A. 1 kmph B. 5 kmph C. 8 kmph D. 3 kmph

Answer 1

Heya !!

Man's speed with the current = 15 km/hr
=> speed of the man + speed of the current = 15 km/hr

speed of the current is 2.5 km/hr
Hence, speed of the man = 15 - 2.5 = 12.5 km/hr

man's speed against the current = speed of the man - speed of the current
= 12.5 - 2.5 = 10 km/hr

Answer 2

B. 5 kmph
This is because;
If speed of boat=x
And speed of river=y
Then,
x-y=4 [x=4+y___{1}]
x+y=6 {2}
Substituting eqn. 1 in 2
4+y+y=6
2y=6-4
y=2/2
y=1 {3}
Sub. Eqn. 3 in 1
x=4+y
x=4+1
x=5
Hence, speed of boat is 5 kmph.

Hope this helps you!!
Please mark as brainliest!