In a class of 7, there are 3 students who have done their homework.
If the teacher chooses 3 students, what is the probability that none of the three of them have done their
homework?

What is the value of the digit 1 in the number 13?

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

Peter applied to an accounting firm and a consulting firm. he knows that 30% of similarly qualified applicants receive job offers from the accounting firm, while only 20% of similarly qualified applicants receive job offers from the consulting firm. assume that receiving an offer from one firm is independent of receiving an offer from the other. what is the probability that both firms offer peter a job?