Twelve students in a class average 70% on a certain test. eighteen others average 80%. what is the overall average of the thirty students as a percent

Given:

12 students average 70%

18 students average 80%

What is the overall average of the 30 students as a percent?

12 x 70% = 840%

18 x 80% = 1440%

840% + 1440% = 2280%

2280% / 30 = 76%

The overall average of the 30 students is 76%.