Calculate how much time could be saved if the train would run at its usual speed, given that it ran at 4/9 of its own speed and got to its destination in 13 hours?  Choose the most appropriate option
A) 1.22 hrs	B) 2.22 hrs	C) 5.22 hrs	D) 6.22 hrs	E) 7.22 hrs

Rationale: "new speed = 4 / 9 of usual speed new time = 4 / 9 of usual time 4 / 9 of usual time = 13 hrs usual time = 13 * 4 / 9 = 5.78 hrs time saved = 13 - 5.78 = 7.22 hrs answer is e"
Answer: E