Can you place six X (crosses) in below board without making three in a row in any way ?

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

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

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

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

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

What breaks yet never falls, and what falls yet never breaks?