Two laborers sand the hardwood floor of an events hall in 9 hours. a) How long would it take if three laborers worked together given that they have the same abilities?
b) How many workers would be needed to finish in 4 hours or less?

PLS help 20 points !!

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

If you are just building your payment history, how many points from a perfect score will you possibly miss?

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?