When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

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

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

John was visiting his friend Jacob. He found out that his friend's wife had just killed a burglar in self-defense.
John asks Jacob about what happened and he told that "His wife was watching television when suddenly the bell rang. She thought that it is her husband Jacob but she found the burglar who attacked her instantly and she got so frightened that she killed the burglar immediately with the knife.
John asked the police to arrest his friend's wife. Why?

A solo dice game is played. In this game, upon each turn, a normal pair of dice is rolled and the score is calculated not by adding the numbers but multiplying them.

In a particular game, the score for the second roll is five more than what was achieved in the first roll. The score for the third roll is six less than what was completed in the second roll. The score for the fourth roll is eleven more than what was achieved in the third. The score for the fifth roll is eight less than what was completed in the fourth.

Can you calculate the score for each of the five throws?

Using eight eights and addition only, can you make 1000?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?