Multiply 9/20 and 5/35

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?