Five friends attend a matinee movie and spend $8 per ticket. They also purchase a small bag of popcorn each. If the friends spend a total of $62.50, how much does each small bag of popcorn cost?

Formula: (cost of ticket + cost of popcorn) * # of friends = total cost

Which would give us (8 + x) * 5 = 62.5

Solve for x.

8 + x = 12.5 {divide each side by 5}

x = 12.5 - 8

x = 4.5

Each small bag of popcorn costs $4.50.