Question 601195: A boat can go 104mph in still water. It takes as long to go 300miles upstream as it does to go downstream 350miles. How fast is the current? Answer by mananth(16946) (Show Source):
speed against current 104 - x
speed with current 104 + x
Distance against current 300 km
Distance with current 350 km
t=d/r time against = time with current
300 / ( 104 - x )= 350 / ( 104 + x
300 ( 104 + x )= 350 ( 104 -x )
31200 + 300 x = 36400 - -350 x
350 x 300 x = 36400 + -31200
650 x = 5200
/ 650
x = 8 km/h current speed
