A paddling canoeist took 2 h to travel 12 km down a river, with the current. It took 4 h to do the return trip up the river, against the current. What was the speed of the current
12 / 2 = 6 km/h - his speed with the current
12 / 4 = 3 km/h - his speed against the current.
[6 - 3 ] / 2 =1.5 km/h - the speed of the current.
+128474 Call the current spped, C
Call the speed of the boat in still water, R
Effective rate with current = R + C
Effective rate against the current = [ R - C ]
So we have that distamce / rate = time...so...
12/ [ R + C] = 2 12 /[ R - C] = 4
12 = 2 [ R + C] 12 = 4 [ R - C]
6 = R + C 3 = R - C
Add the last two equations
9 = 2R
4.5 = R
And
6 = R + C
6 = 4.5 + C
1.5 = C
