Simplidy y square root 6 over 6 square root y

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?

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

What is 100,000 times 1/100,000, using the standard method of multiplication? write the answer as 10 to a power.