Question 840750
How much of a head start does Chantel get from
8:00 to 8:15 ?
{{{ d[1] = 65*(1/4 ) }}} ( 15 min is 1/4 hr )
{{{ d[1] = 16.25 }}}
Start a stopwatch when her mom leaves at 8:15
Let {{{ d }}} = the distance in miles that her mom
travels until she catches her daughter
Let {{{ t }}} = the time in hrs on the stopwatch when
her mom catches up with her
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Chantel's equation:
(1) {{{ d - 16.25 = 65t }}}
Mom's equation:
(2) {{{ d = 72t }}}
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By substitution:
(1) {{{ 72t - 16.25 = 65t }}}
(1) {{{ 7t = 16.25 }}}
(1) {{{ t = 2.321 }}}
{{{ .321*60 = 19.286 }}}
{{{ .286*60 = 17 }}}
It will take her mom 2 hrs 19 min 17 sec
to catch Chantel
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check:
(1) {{{ d - 16.25 = 65*2.321 }}}
(1) {{{ d = 150.865 + 16.25 }}}
(1) {{{ d = 167.115 }}}
and
(2) {{{ d = 72*2.321 }}}
(2) {{{ d = 167.112 }}}
close enough