Jamie bought two puzzles for $5.00 and three puzzles for $7.50. Write and solve an equation to find the cost of 15 puzzles

Agroup of five people go out to eat and buy appetizers and main dishes they decide to split the bill so each person pays 20% of the total cost appetizers are $5 and main dishes are $10 write an expression to show how much each person pays explain it with how to solve the problem