11. in the diagram below ap is tangent to circle o at point a, ob = 7, and bp = 18. what is the length of
ap?

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.