Question

about man can row downstream 20 km in 2 hour and upstream 4 km in 2 hours find Board Maths speed of rowing in still water and speed of the water current

Answer 1

hiiii guy
here is your answer
assuming the speed os the stream be "k" and the speed of the boat be "f".
so,
I case
$speed = \frac{distance}{time} \\f + k = \frac{20}{2} \\f + k = 10km {hr}^{ - 2}$
now, II case
$speed= \frac{distance}{time} \\ f - k = \frac{4}{2} \\ f- k = 2km {hr}^{ - 2}$
now as
f -k =2 and
f+k =10

so, speed of boat=6km/hr
and speed of stream=4km/hr


glad to help you
hope it helps
thank you.