What is the next number in this series?

4,12,84,3612....

What can you hold in your right hand, but never in your left hand?

Replace the question mark with the correct number below.

You can hear me, but you can't touch or see me.

What am I?

There is a basket full of hats. Three are white and two are black. Three men, Tom, Tim, and Jim, each take a hat out of the basket and put it on their heads without seeing the hat they selected or the hats the other men selected. The men arrange themselves so Tom can see Tim and Jim’s hats, Tim can see Jim’s hat, and Jim can’t see anyone’s hat. Tom is asked what color his hat is and he says he doesn’t know. Tim is asked the same question, and he also doesn’t know. Finally, Jim is asked the question, and he does know. What colour is his hat?

Who is that with a neck and no head, two arms and no hands? What is it?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Can you divide numbers from 1 to 9 (1 2 3 4 5 6 7 8 9) into two groups so that the sum of the numbers of each group is equal?

Note: 9 cannot be turned over to make it 6.

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?