Sin(45^degrees)=13/x

Can somebody me out with this question

Three coins are flipped. what is the probability that there will be at least two tails?

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done