Answer:
A=368 miles
B= 356.3 miles
Step-by-step explanation:
Given data
Let the two trains be A and B
A+B=724.3----------1
A-B=11.7--------------2
From eqn 1
A= 724.3-B
put this in place of A in eqn 2
724.3-B-B= 11.7
724.3-2B= 11.7
724.3-11.7= 2B
712.6=2B
B= 712.6/2
B= 356.3 miles
Put B=356.3 in eqn 1
A+356.3=724.3----------1
A= 724.3-356.3
A=368 miles
