Question 927488
Let {{{ s }}} = the speed of the boat in still water in mi/hr
Let {{{ c }}} = the speed of the current in mi/hr
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{{{ s - c }}} = the speed of the boat going upstream
{{{ s + c }}} = the speed of the boat going downstream
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Equation for going upstream:
(1) {{{ 224 = ( s - c )*8 }}}
Equation for going downstream:
(2) {{{ 224 = ( s + c )*7 }}}
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(1) {{{ 8s - 8c = 224 }}}
(2) {{{ 7s + 7c = 224 }}}
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(1) {{{ s - c = 28 }}}
(2) {{{ s + c = 32 }}}
Add the equations
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{{{ 2s = 60 }}}
{{{ s = 30 }}}
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(1) {{{ 30 - c = 28 }}}
(1) {{{ c = 2 }}}
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The speed of the boat in still water is 30 mi/hr
The speed of the current is 2 mi/hr
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check:
(1) {{{ 224 = ( 30 - 2 )*8 }}}
(1) {{{ 224 = 224 }}}
OK
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