Find the number of possible choices for a 4-digit (pin) if the digits cannot be repeated find the possible choices of a 4-digit (pin) if the digits cannot be repeated

In the diagram of circle a what is m

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Hardest math question of all time can you solve the equation. check for extraneous solutions.9∣9-8x∣ = 2x+3