What breaks yet never falls, and what falls yet never breaks?

Prove that the below maths equation is true.

8 + 8 = 91

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What month of the year has 28 days?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Jack have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the colour of the socks. How many of the socks did he want to take to match one pair

It belongs to you, but other people use it more than you do. What is it?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91