Bella bought 3 bags of popcorn for $8.25 and 2 sodas for $4.40 at the movies last week. Last month, Bella was at the movies with her friends and bought 3 bags of popcorn for $7.50 and 2 sodas for $3.80. What was the percent increase?

bags of popcorn = 10%

sodas = 15.78%

overall increase was 12.5%

Step-by-step explanation:

We must calculate the unit price of each product, before and after.

Before:

bags of popcorn = 7.50 / 3 = 2.5

sodas = 3.80 / 2 = 1.9

Then:

bags of popcorn = 8.25 / 3 = 2.75

sodas = 4.40 / 2 = 2.2

Now, we calculate for each:

bags of popcorn = 2.75 / 2.5 = 1.1

which means that the increase was 10%

sodas = 2.2 / 1.9 = 1.1578

Which means that the increase was 15.78%

If we calculate the percentage of total increase it would be:

(2.75 + 2.2) / (2.5 + 1.9) = 1,125

Therefore the overall increase was 12.5%