Question

a certain boat downstream covers a distance of 16 km in 2 hours downstream while covering the same distance upstream, it takes 4 hours. what is the speed of the boat in still water and the speed of the stream ​

Answer 1

Answer:speed of boat in still water:6 Kmph

speed of stream is:2 kmph

Step-by-step explanation:

Basic concept is in downstream the boat is going in the direction of stream and thus it has more speed

in upstream the boat is going against the direction of stream so it has less speed

Now speed of boat be X

Speed of stream be Y

downstream:X+Y= 16 km / 2 hours (we know speed=distance/time)

X+Y=8    --- -1 ;X=8-Y

upstream:X-Y=16 hours/4 hours

X-Y=4    ------2

Solving both using substitution

8-Y-Y=4

8-2Y=4

4=2Y

Y=2 kmph i.e speed of stream is 2 kmph

X=8-2=6 kmph

speed of boat in still water is:6 kmph