Average Scores Difference - Class A and Class B

A statistical analysis was conducted on the test scores of three classes of students who took a mathematics exam. The results of the test scores (out of 100) are as follows:

Class A: 70, 75, 80, 85, 90

Class B: 60, 68, 72, 75, 80

Class C: 78, 82, 88, 90, 95

The average score of each class can be calculated using the formula:

Average score = $$\frac{Sum ext{ of scores}}{Number ext{ of students}}$$

Based on these scores, what is the difference in average scores between Class A and Class B?