1. ## Distance formula confusion

The question below states that at noon, Deirdre and Donovan were 1100 miles apart? According to the question, Deirdre boarded the train at 12pm and Donovan 2 hours later. Is there a typo in this book or am I missing something?

Deirdre and Donovan are in love and will be meeting in Kansas City to get married.
Deirdre boarded a train at noon traveling due east toward Kansas City. Two hours later, Donovan boarded a train traveling due west, also heading for Kansas City, and going at a rate of speed 20 miles per hour faster than Deirdre. At noon, they were, 1,100 miles apart. At 9 pm. they, they both arrived at Kansas City. How fast are they traveling?

Distance of Deirdre from Kansas City + Distance of Donovan from Kansas City = 1,100
Rate x Time + Rate x Time = 1,100

2. ## Re: Distance formula confusion

Let a mph = Deirdre's speed;
so Donovan's speed = a+20 mph

time by Deirdre = 9 hours; so:
distance by Deirdre = 9a;
so distance by Donovan = 1100 - 9a

time by Donovan = 7 hours; so:
distance by Donovan also = 7(a + 20); so:
1100 - 9a = 7(a + 20)

Solve for a