Question 50914
We dont have enough information to solve this one.  Looking at the eastbound plane, we know it traveled for 3 hours, but we don't know how far, or how fast they were going.  Same with the westbound plane.

If we ASSUME that they are traveling at the SAME speed, that means they are equally distant from their starting point, 1350 miles away  Using this and the three hour travel time ....

{{{ RT=D }}}
{{{ R(3)=1350 }}}
{{{ R=450 }}}

So they would have been traveling at 450 MPH

Remember though, this is ASSUMING that they traveled at the same rate.