Mr. Bobby Fischer (1943-2008) is one of the finest Chess player ever known. Just in the age of 18 he supposed to play 8-different champion ships in a year. To become World champion he must won 6 of them. What is the probability that he won at least 5 of them? (For your interest: He won all of them and become youngest Chess World Champion in 1951.)

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?