Question 346100
Equation 1) a = b-8
Equation 2) at = 200
Equation 3) bt = 240

Equation 2) t = 200/a
Equation 3) t = 240/b
Combine equation 2 & 3:
200/a=240/b
200b = 240a
b = 240a/200
b = 6a/5


Substitute into Equation 1:
a = 6a/5 – 8
8 = a/5
a = 40 mph
b -8 = 40 mph
b = 48 mph

Answer
Train A is moving at 40 mph.
Train B is moving at 48 mph.