Question 134828
Rate of boat in still water = {{{b}}}
Rate of stream = {{{s}}}
{{{b - s = 11}}}
(1) {{{b = 11 + s}}}
(2) {{{b + s = 25}}}
Substitute (1) in (2)
{{{11 + s + s = 25}}}
{{{2s = 14}}}
{{{s = 7}}}
(1) {{{b = 11 + s}}}
{{{b = 11 + 7}}}
{{{b = 18}}}
The rate of the stream is 7 km/hr and the rate of the boat
in still water is 18 km/hr