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

Count the number of triangles in the given picture.

I can be cracked, made, told, and played. What am I?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

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?

Can you solve the below tricky visual equation?

Identify the hidden meaning behind this picture?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?