Word Prob.: Find the speed of the boat in still water.

I am struggling with this.

Alvin paddled for 2 hours with a 8-km/h current to reach a campsite. The return trip agains the same current took 10 hours Find the speed of the boat in still water.

Re: word

I am struggling with this.

Alvin paddled for 2 hours with a 8-km/h current to reach a campsite. The return trip agains the same current took 10 hours Find the speed of the boat in still water.

Using V = D/T

Let Vb = the speed of the boat.
Then, D/(Vb + 8) = 2 and D/(Vb - 8) = 10
Solving each for D and equating the results yields 2Vb + 16 = 10Vb - 80 making Vb = 12 km/hr and D = 40 km.

40/(12 + 8) = 2 and 40/(12 - 8) = 10.

b = boat speed
2(b + 8) = 10(b - 8) ; solve for b

REMEMBER: speed = distance / time