Question 602880
Soren's head start was {{{ 36 }}} mi
Start a stop watch when Eric leaves.
Let {{{ d }}} = distance that Eric travels
Let {{{ s }}} = Soren's speed
They will both travel for the same amount of time, {{{ 3 }}} hrs
until Soren is caught.
Soren's equation:
(1) {{{ d - 36 = s*3 }}}
Eric's equation:
(2) {{{ d = 2s*3 }}}
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This is 2 equations and 2 unknowns, so it's solvable
Substitute (2) into (1)
(1) {{{ 6s - 36 = 3s }}}
(1) {{{ 3s = 36 }}}
(1) {{{ s = 12 }}}
{{{ 2s = 24 }}}
Eric's speed is 24 mi/hr
check:
(1) {{{ d - 36 = s*3 }}}
(1) {{{ d - 36 = 12*3 }}}
(1) {{{ d = 36 + 36 }}}
(1) {{{ d = 72 }}}
and
(2) {{{ d = 2s*3 }}}
(2) {{{ d = 2*12*3 }}}
(2) {{{ d = 72 }}}
OK