Question 1021145
Assuming the distances upstream and downstream are the same, then:
2.5(x-2.5)kmh=1.5(x+2.5)kmh
2.5x-6.25=1.5x+3.75
1x=10 kmh in still water......
1.5(10+2.5)=18.75 kilometers to her friend's house!!!!!!