Question 1108099
How far did the car get in {{{ 1.5 }}} hrs ?
{{{ d[1] = 40*1.5 }}}
{{{ d[1] = 60 }}} mi
Start a stop watch when the bus leaves
Let {{{ t }}} = time in hrs on stop watch 
when the bus catches the car
Let {{{ d }}} = distance in miles the bus 
travels until it catches the car
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Equation for the bus:
(1) {{{ d = 60t }}}
Equation for the car:
(2) {{{ d - d[1] = 40t }}}
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(2) {{{ d - 60 = 40t }}}
Plug (1) into (2)
(2) {{{ 60t - 60 = 40t }}}
(2) {{{ 20t = 60 }}}
(2) {{{ t = 3 }}}
It will take the bus 3 hrs to catch up with the car
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check:
(1) {{{ d = 60t }}}
(1) {{{ d = 60*3 }}}
(1) {{{ d = 180 }}}
and
(2) {{{ d - 60 = 40t }}}
(2) {{{ d - 60 = 40*3 }}}
(2) {{{ d - 60 = 120 }}}
(2) {{{ d = 180 }}}
OK