Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

What has many keys but can’t open a single lock?

What can jump higher than a building?

What is full of holes but still holds water?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

I look at you, you look at me, I raise my right, you raise your left. What am I?

There are 4 big houses. They are made from the materials: red marble, green marble, white marble and blue marble.

* Mrs Jennifer's house is somewhere to the left of the green marble one and the third one alone is white marble.
* Mrs Sharon owns a red marbles house and Mr Cruz does not live at either end, but lives somewhere to the right of the blue marbles house.
* Mr Danny lives in the fourth house, while the first house is not made from red marble.

Who lives where, and what is their house made from?

What number should come in place of the question mark below?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

The more of this there is, the less you see. What is it?