Question 1144623
Let {{{ r }}} = rate of boat in still water
Let {{{ c }}} = rate of current
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Equation for going upstream ( against the current )
(1) {{{ 145 = ( r - c )*5 }}}
Equation for going downstream ( with the current )
(2) {{{ 205 = ( r + c )*5 }}}
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(1) {{{ 29 = r - c }}}
(2) {{{ 41 = r + c }}} Add the equations
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{{{ 70 = 2r }}}
{{{ r = 35 }}} mi/hr
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Plug this result back into either equation
(1) {{{ 145 = ( 35 - c )*5 }}}
(1) {{{ 29 = 35 - c }}}
(1) {{{ c = 35 - 29 }}}
(1) {{{ c = 6 }}} mi/hr
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check:
(2) {{{ 205 = ( r + c )*5 }}}
(2) {{{ 205 = ( 35 + 6 )*5 }}}
(2) {{{ 205 = 41*5 }}}
(2) {{{ 205 = 205 }}}
OK