14 POINTS!! PLS ANSWER

He amount of carbon-14 present in animal bones t years after the animal's death is given by p(t)equals=upper p 0 e superscript negative 0.00012097 tp0e−0.00012097t. how old is an ivory tusk that has lost 26% of its carbon-14?

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

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?