Math question 1, thanks if you help:)

Jordan got 27 out of 90 correct on his test . what fraction of the marks did her get correct

To decrease an amount by 16% what single multiplier would you use

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?