Using mental math, the approximate tip to leave for a bill of $81.79, if you tip 15% would be .. a. $8.20 b. $10.30 c. $12.30 d. $16.40 Please select the best answer from the choices provided A B C D

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?

Use the distributive law to multiply. 3(4x + 5y + 6)

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).