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

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

How many sides does a circle have?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

Which Travels Faster? Solve below famous picture riddle:

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

A man looks at a painting in a museum and says, “Brothers and sisters I have none, but that man’s father is my father’s son.” Who is in the painting?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?