4out of every five visitors at an amusement park by day passes what percent of the visitors buy day passes

What is the simplified expression for 6(2(y+x))

Which equation represents the partial sum of the geometric series?

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?