Why did the Girl throw the butter out of the window?

Find the next number in the series below

21 32 54 87 131 ?

Why Aeroplane windows are round?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

what does the below rebus means?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

What is the end of everything?

Find the number of squares in the below picture

Trying to tease Birbal, Akbar gave him one gold coin and ask him to buy
* something for him to eat
* something for him to drink.
* something to feed the cows
* something to plant in the garden
and most important you need to buy only one thing.

What must Birbal buy to silence Akbar?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?