larkinjohnpaul
12-06-2009, 03:20 PM
...of boat in still water is 15km/h.? Find the speed of the current(this is in a rational equations section of my math book if that helps)
Astaloph
12-06-2009, 04:40 PM
Distance Upstream = (B - W)T where B = speed of boat in still water, W = speed of current, and T = Time.so,35km = (15km/hr - W)(4.8)W = 7.71 km/hr
fredoniahead
12-06-2009, 05:57 PM
Since d=rt, then t=d/rHis rate upstream against the current is 15-r and his rate downstream with the current is 15+r. He travels this in 4-4/5 hors or 24/5 hours.35/(15+r)+35/(15-r)=24/5Solve for r=5/2 or 2.5 km/hr is the rate of the current.