Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

Move four matchsticks to the below square to form three squares?

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?

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

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

Complete the table series riddle by finding the number that can replace "??".

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

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?