I’m tall when I’m young, and I’m short when I’m old. What am I?

Find the next number in the series below

21 32 54 87 131 ?

Which alphabet is a part of our body?

No matter how little or how much you use me, you change me every month. What am I?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

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

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

A journalist was investigating a sacred cult in the jungles of Africa when he was caught by one of the person. He was confined in a cave till the leader arrived. The leader told him that he need to tell him a statement. If he thinks the statement is true, then the journalist head will be chopped off. If he thinks that the statement is false, his head will be smashed with a hammer.

What statement did the journalist make to survive?