Question 834275
Question Number 2 is faulty.  We are not given all the directions in which Jim traveled.  South for one part, but what about the other parts?


Question Number 1:
That is like asking "what is the sum of their distances" after the given amount of fly time.  The two planes are going in opposite directions.


1 hour 20 minutes is the same as {{{1&1/3}}} hours;
{{{480*1&1/3+600*1&1/3}}}, which simply uses Rate*Time=Distance.
{{{(1&1/3)(480+600)}}}
{{{(1&1/3)(1080)}}} miles...