Question 867370
Let {{{ t }}} = the time in hours to arrive on time
{{{ d = r*t }}}
{{{ 100 = m*( t + 1 ) }}}
{{{ 100 = m*t + m }}}
{{{ m*t = 100 - m }}}
{{{ t = ( 100 - m ) / m }}}
------------------------------
{{{ 100 = r*( 100 - m ) / m }}}
{{{ r = 100m / ( 100 - m ) }}}
is the rate to arrive on time
-----------------------------------
check:
Suppose {{{ m = 75 }}}
{{{ 100 = m*( t + 1 ) }}}
{{{ 100 = 75*( t + 1 ) }}}
{{{ t + 1 = 4/3 }}}
{{{ t = 1/3 }}}
----------------------
{{{ r = 100m / ( 100 - m ) }}}
{{{ r = 100*75 / ( 100 - 75 ) }}}
{{{ r = 7500 / 25 }}}
{{{ r = 300 }}}
---------------------
{{{ d = r*t }}} 
{{{ 100 = 300*t }}}
{{{ t = 1/3 }}}
OK