Question 1159721


given:

{{{d=84mil}}}
{{{t=4h}}}


Let {{{ s }}} = the speed of the slower jogger in {{{mil/h}}}
{{{ s + 3 }}} = the speed of the faster jogger in {{{mil/h}}}
Let {{{ d }}} = the distance the slower jogger has to run until they meet
{{{ 84 - d }}} = the distance the faster jogger runs


Equation for slower jogger:

(1) {{{ d = s*4 }}}

Equation for faster jogger:

(2) {{{ 84 - d = ( s + 3 )*4 }}}


Substitute (1) into (2)

 {{{ 84 - 4s = ( s + 3 )*4 }}}
{{{ 84 - 4s = 4s + 12 }}}
{{{ 84-12 = 8s }}}
 {{{ 72 = 8s }}}
 {{{ s = 9}}}

and

{{{ s + 3 = 12 }}}

{{{9( mil/h)}}} is the speed of the slower jogger
{{{12(mil/h)}}} is the speed of the faster jogger

then distance that slower jogger runs to meet faster jogger  is {{{ d = 9*4 =36mil}}} 

{{{ 84 - 36 = 48 mil}}}->  distance faster jogger  runs to meet slower jogger

the sum of distances is {{{36mil+48mil=84mil}}}