If x and y are positive integers such that 5x+3y=100, what is the greatest possible value of xy? please include steps. Thank you!

When turned about its axis of rotation, which shape could have created this three-dimensional object?

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?

Solve x+3y=6 and 4x-6y=6 by elimination . show work !