Tell whether the number belongs to each of the following number sets
12/3

What situation is an example of an observational study

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan 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?

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.