Question 993248
{{{ 28 }}}  min
{{{ 28/60 = 7/15 }}} hr
and
{{{ 12 }}} min
{{{ 12/60 = 1/5 }}} hr
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Equation for rowing upstream:
(1) {{{ d = ( 5 - x )*( 7/15 ) }}}
Equation for rowing downstream:
(2) {{{ d = ( 5 + x )*( 1/5 ) }}}
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(1) {{{ d = 7/3 - ( 7/15 )*x }}}
and
(2) {{{ d = 1 + ( 1/5 )*x }}}
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Substitute (1) into (2)
(2) {{{ 7/3 - ( 7/15 )*x = 1 + ( 1/5 )*x }}}
Multiply both sides by {{{ 15 }}}
(2) {{{ 35 - 7x = 15 + 3x }}}
(2) {{{ 10x = 20 }}}
(2) {{{ x = 2 }}}
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The speed of the current is 2 mi/hr
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(2) {{{ d = 1 + ( 1/5 )*x }}}
(2) {{{ d = 1 + ( 1/5 )*2 }}}
(2) {{{ d = 1.4 }}}
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The 2-way distance is {{{ 2*1.4 = 2.8 }}}
2.8 mi total distance traveled
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check:
(1) {{{ d = ( 5 - x )*( 7/15 ) }}}
(1) {{{ 1.4 = ( 5 - 2 )*( 7/15 ) }}}
(1) {{{ 1.4 = 7/5 }}}
(1) {{{ 1.4 = 1.4 }}}
OK