There are $15$ gymnasts in the Olympic women's competition, including $4$ Americans. The gold medal goes to first place, silver to second, and bronze to third. In how many ways can the medals be awarded to three of the $15$ gymnasts, if exactly one of the Americans wins a medal?

Meghan has created a diagram of her city with her house, school, store, and gym identified. a. how far is it from the gym to the store? b. meghan also wants to walk to get some exercise, rather than going to the gym. she decides to walk along arc ab. how far will she walk? round to 3 decimal places.