Question 1062633
Think of this as one of the cars standing still
and the other traveling at the sum of their speeds
until it meets the other car
Let {{{ t }}} = time in hrs until they meet
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{{{ 42 = ( 60 + 80 )*t }}}
{{{ 42 = 140t }}}
{{{ t = .3 }}} hrs
Convert hrs to minutes
{{{ .3*60 = 18 }}}
They will meet in 18 min
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Check answer:
{{{ d[1] = 60t }}}
{{{ d[1] = 60*.3 }}}
{{{ d[1] = 18 }}} km
and
{{{ d[2] = 80t }}}
{{{ d[2] = 80*.3 }}}
{{{ d[2] = 24  }}} km
and
{{{ 18 + 24 = 42 }}} km
OK