Which mathematical property is demonstrated?

(25 + 84) + 16 = 25 + (84 + 16)

The table shows the balance of a money market account over time. write a function that represents the balance y (in dollars) after t years.

Student price tickets to a movie are $1 and non student tickets are $2 . 350 tickets are sold and the total amount made is $450. there were 250 student tickets sold . true or false .

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?