I have been trying to figure out this problem for an hour no

I have been trying to figure out this problem for an hour now I cannot get the answer the book gives me in the back. I found the problem here on your site already but the answers are not the same as the back of my book either.
This is the link to the problem on your site, http://www.algebra.com/algebra/homework/word/travel/Travel_Word_Problems.faq.question.164399.html
The problem is the same as in my book but the answers in the back say it should be : 2 hr at 50 mph and 3 hr at 40 mph.

Solution

This is an RTD problem. Here is a table based on the given information.
bus . . . . . . . . .rate . . . . . . . . .time . . . . . . . . . distance
. . . . . . . . . . . . 50 . . . . . . . . . . t . . . . . . . . . . . . .50t
. . . . . . . . . . . . 40. . . . . . . . . 5 - t . . . . . . . . . . . 200 - 40t
. . . . . . . . . . . . . . . . . . . . . . . .5. . . . . . . . . . . . . .220
from column 3 we get
50t + 200 - 40t = 220
combine like terms and we get
10t + 200 = 220
subtract to get
10t = 20
t = 2
5 - t = 3
50 mph for 2 hours
40 mph for 3 hours