Question 347785
Downstream:
rate = {{{s + c}}}
{{{12 = (s + c)*1}}}
Upstream:
rate = {{{s - c}}}
{{{12 = (s - c)*2}}}
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(1) {{{s + c = 12}}}
{{{2s - 2c = 12}}}
(2) {{{s - c = 6}}}
Add (1) and (2)
{{{2s = 18}}}
{{{s = 9}}}
{{{s + c = 12}}}
{{{c = 12 - 9}}}
{{{c = 3}}}
The speed of the boat in still water
is 9 km/hr
The speed of thr current is 3 km/hr