Aclass has 6 and 15 girls. what is the ratio of boys and girls?

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?

Find the solution of each of the following.

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.