Let a and b be nonempty bounded subsets of r(real numbers), and let a+b be the set of all sums a+b where a∈a and b∈b.

a)prove sup(a+b)= supa + supb (hint: to show supa+supb
b)prove inf(a+b)= infa+infb

Can someone answer this question? : )

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?

George is putting trim around his rectangular deck, including the gate. he will need 44 feet of trim to do the entire deck. if the deck is 13 feet long, how wide is the deck?