Question 784002
Suppose the route from San Fran to L.A is a straight line. If the two trains travel at the same speed and depart at the same time, they should meet at the center point of this line. The total distance is 400 miles, so half of it is 200 miles.
The time it takes to travel 200 miles = 200/80 = 2.5 hours, thus the two will meet at 10:30 AM (= 8 + 2.5).