Question 1050751
Let {{{ s }}} =the speed of T to O train in km/hr
{{{ s + 10 }}} = the speed of the O to T train in km/hr
Let {{{ d }}} = the distance in km  the T to O train travels until they meet
{{{ 350 - d }}} = the distance in km the O to T train travels until they meet
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Equation for T to O train:
(1) {{{ d = s*2.5 }}}
Eqation for O to T train:
(2) {{{ 350 - d = ( s + 10 )*2.5 }}}
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Substitute (1) into (2)
(2) {{{ 350 - 2.5s = ( s + 10 )*2.5 }}}
(2) {{{ 350 - 2.5s = 2.5s + 25 }}}
(2) {{{ 5s = 325 }}}
(2) {{{ s = 65 }}}
and
{{{ s + 10 = 75 }}}
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The T to O train travels 65 km/hr
The O to T train travels 75 km/hr
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check:
(1) {{{ d = s*2.5 }}}
(1) {{{ d = 65*2.5 }}}
(1) {{{ d = 162.5 }}}
and
(2) {{{  350 - d = ( s + 10 )*2.5 }}}
(2) {{{  350 - d = 75*2.5 }}}
(2) {{{ d = 350 - 187.5 }}}
(2) {{{ d = 162.5 }}}
OK