Question

In a student body election, 5% of the eligible voters are aged 18-21 years, 12% are aged 21-25 years, and the rest are older than 25 years. Among these groups, 80% of the 18-21 year age group and 60% of the 21-25 year age group actually voted. If the number of voters aged 21-25 years who voted exceeds those aged 18-21 years by 320, what is the difference between the number of eligible voters aged 18-21 years and those aged 21-25 years?