If 21% of the customers in a restaurant order fish, what is the probability that the next 3 costumers in a row will order fish?

Ineed big ! the cost of a school banquet is $25 plus $15 for each person attending. create a table, sketch the graph, and write an equation in slope-intercept and point-slope form that gives total cost as a function of the number of people attending. what is the cost for 77 people?