Question 581149
let the distance the boat travels be x km

upstream speed = 25-10=15 km/h

down stream speed = 25+10 = 35 km/h

Time upstream + time down stream = 12

t=d/r

{{{x/15 + x/35 = 12}}}

LCD =105

multiply by the LCD

7x+3x=105*12

10x= 1260

/10
x=126 km