Question 1126195
dd their speeds since they travel towards each other
(1) {{{ 240 = ( x + y )*3 }}}
Next Murray gets a 1 hr head start. In 1 hr, he travels:
{{{ d[1] = y*1 }}} km
Start counting time when Mary leaves
(2) {{{ 240 - y = ( x + y )*2.5 }}}
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(2) {{{ 240 - y = 2.5x + 2.5y }}}
(2) {{{ 2.5x + 3.5y = 240 }}}
and
(1) {{{ x + y = 80 }}}
(1) {{{ 2.5x + 2.5y = 200 }}}
subtract (1) from (2)
{{{ y = 40 }}}
and
(1) {{{ x + 40 = 80 }}}
(1) {{{ x = 40 }}}
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They both travel at 40 km/hr
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check:
(2) {{{ 240 - y = ( x + y )*2.5 }}}
(2) {{{ 240 - 40 = ( 40 + 40 )*2.5 }}}
(2) {{{ 200 = 80*2.5 }}}
(2) {{{ 200 = 200 }}}
OK