Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

A guy in his thirties is found dead in a forest. The shocking thing about the body is that he is wearing his swimming trunks snorkel and a facemask.

For your information, the nearest lake is some 10 miles away and the sea is hundreds of miles away.

How did he die then?

Can you identify if it's a murder or a suicide ?

Before Mount Everest was discovered, what was the highest mountain in the world?

What is the next number in this series?

4,12,84,3612....

In the four images below, can you find the odd one out?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?