In a shipment of 22 smartphones, 2 are defective. How many ways can a quality control inspector randomly test 4 smartphones, of which 2 are defective? (a) there are no restrictions on the order
(b) all the bands of each type must perform in a row

Bella want to know what the students at her school think of her show. which is the best group to survey to find this information a. go to the mall and ask all of the students she recognizes from school b. ask her viewers to call in durning an episode of the show c. get a list of students at her school from the office and use a random number generator to pick 30 of them d. get a list of students at her school from the office and pick the first 30 students on the list