t = d / r
[6 / (9 - c)] + [6 / (9 + c)] = 8/3 hr
6(9 + c) + 6(9 - c) = 8/3(81 - c^2)
108 = 216 - (8/3 c^2) ... 0 = 108 -(8/3 c^2)
use quadratic formula to find c
A fisherman traveled in a boat from point N upstream. After having traveled 6 km, he stopped rowing and 2 hour 40 min after first leaving N, he was brought back to N by the current. Knowing that the speed of the boat in still water is 9 km/hour, find the speed of the river’s current.
3 answers
Thx!
But, so is c the speed