Which has a value closest to 9?

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?

The answer is 7.2 how would you put this as money

Suppose you have 10 skittles. 5 green and 5 red. you choose 4 without looking. what is the probability that all 4 skittles will be green?