Answer:
2.2 h
Step-by-step explanation:
v = s/t ⇒ s = vt
First train:
v₁ = 90 mph - the speed
t - the time to meet
s₁ = s - the distance to meet
s₁ = v₁t
s = 90t
Second train:
v₂ = 100 mph - the speed
t - the time to meet
s₂ = 418-s - the distance to meet
s₂ = v₂t
418 - s = 100t
-s = -418 + 100t
s = 418 - 100t
90t = 418 - 100t
90t + 100t = 418
190t = 418
t = 2.2 h
