Betty leaves her home and walks toward Dave's house. Two hours later, Dave leaves his home and walks toward Betty's house. The distance between their homes is 36 kilometers, Betty's walking speed is 4 km/h, and Dave's walking speed is 3 km/h. How many kilometers will Betty walk before she meets Dave? Options
A) 18	B) 20	C) 22	D) 24	E) 25
Betty walks 8 km in the first two hours so there are 28 km remaining.   When Dave starts walking, they complete a total of 7 km per hour.   They will meet four hours after Dave starts walking.   Since Betty walks for 6 hours, she walks 24 km.   The answer is 24.
<result>D</result>
Betty leaves her home and walks toward Dave's house. Two hours later, Dave leaves his home and walks toward Betty's house. The distance between their homes is 36 kilometers, Betty's walking speed is 4 km/h, and Dave's walking speed is 3 km/h. How many kilometers will Betty walk before she meets Dave?