Three letters are chosen at random from the letters p, a, n, s, o, l. what is the size of the sample space of this experiment? assume that the order of the letters matters. that is, pan is different from apn

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

I’m really confused and need to learn this

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $36.98. find the probability that a randomly selected bill will have an amount greater than $173, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?