In how many different arrangements can the digits 1, 2, 3, 4, 5, 6 be placed in the boxes below, one per box and without repetition, so that the numbers in each row decrease from left to right and the

numbers in each column decrease from top to bottom?

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?