Question 628025
Think of one train as standing still and the other one
traveling away from it at the sum of their speeds
until they are 455 miles apart.
{{{ d = r*t }}}
{{{ 455 = ( 60 + 70 )*t }}}
{{{ 455 = 130t }}}
{{{ t = 455/130 }}}
{{{ t = 3.5 }}}
3.5 hours after 10 AM is 1:30 PM