How do you know that 5, 7, 8, 9, 10, and 11 are not factors of 12?

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

The zoo collects $9.60 for every 24 tickets sold. how much will be collected for 400 tickets?

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?