Question 540666
His time for the 1st 20 miles was
{{{ 20 = 16*t }}}
{{{ t = 1.25 }}} hrs
He needs to finish in less than
 {{{ 2.5 - 1.25 = 1.25 }}} hrs
also
{{{ 50 - 20 = 30 }}} mi
---------------
{{{ v = 30/1.25 }}}
{{{ v = 24 }}}
His speed must be greater than 24 mi/hr