Multiple response: select all correct answers and click "submit." which of the following statements contain a variable? check all that apply. a. there are 60 seconds in a minute. b. double the number of pages in the book. c. he is 15 years old. d. the age of my friend.

B and d because a variable is something that can change. there will always be 60 sec. in a min. , and at that specific time, the boy is fifteen.
hope that makes sense :)

Answer: the correct answer is 10step-by-step explanation: let the number be n, then the expression becomes,then“twelve more than the quotient of a number and two, decreased by four” iswhen n=4,we substitute 4 whetever we see n to get,we simplify to obtain,we further simplify to get,therefore the correct answer is c.