Alibrary is having a book sale to raise money. hard cover books cost $4 each and paperback books cost $2 each. a person spends $26 for eight books. how many hard cover books did she purchase?

In δabc, if the length of side b is 3 centimeters and the measures of ∠b and ∠c are 45° and 60°, respectively, what is the length of side c to two decimal places?

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?

Vertical angles must check all that apply