Find the 20th term of an arithmetic sequence with a first term equals to 5 and the constant difference equals to 10

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?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?