Question

plzzzz answer..... no unwanted answer....

Answer 1

suppose,
speed of stream= x km/h
speed of boat = y km/h
speed= distance/time
time= distance/speed

$\frac{25}{x - y} + \frac{35}{x + y} = 10$
$\frac{40}{x - y} + \frac{49}{ x + y} = 15$
suppose
$\frac{1}{x - y} = a$
$\frac{1}{x + y} = b$
25a+35b=10
40a+49b=15
solve the equation you will get your answer