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.

What word begins and ends with an E, but has only one letter?

Anabelle is a clever trader of rare artefacts. Each day she carries three boxes each filled with thirty artifacts. The boxes can't hold more than that. She travels far in northern lands to sell these artefacts but on the way, she comes across thirty checkpoints where she has to shed one of the artefacts for each sack to the authorities for letting her pass.

How many artifacts will be left with her when she reaches her destination crossing all the checkpoints?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?

In the picture given below, can you find out which digit will take place of the question mark?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

If 21x = 79x, what is the value of x?