Can you me solve an infinite geometric sequence

Someone me! if you’re smart you can solve this!

If the probability of an event happening is 65% then the probability this event does not occur?

The salesperson earns a 5% commission on the first $5,000 she has in sales. the salesperson earns a 7.5% commission on the amount of her sales that are greater than $5,000. this month the sales person had $8,000 in sales. what amount of commission, in dollars, did she earn?