Identify the hidden meaning behind this picture?

I have an eye but still cannot see.

Who am I?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

This is a simple one. You just have to count the number of Fs in the given sentence.

Finished Files are the result of years of scientific study combined with the experience of years.

How many did you count?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

The great emperor Akbar once ruled India. He was well known for his intelligence. But along with that, he was known for the Nine Gems in his court. One of the nine gems was Birbal, a quick witted and extremely intelligent man. The stories of his wit were widely popular.

Once a king ruling in a distant land heard of Birbal. To check his wit, he sent an invitation and called him to visit his land. Akbar allowed Birbal to go and he took off on the journey.

Upon reaching that kings kingdom, he was welcomed with flowers. He was then escorted to the palace of the king. Upon entering the palace, Birbal found that there were six people sitting in front of him adorning the same robe. They were also lookalike and it was hard to judge who the real king was.

After a couple of minutes, Birbal approached one of them and bowed in front of him greeting him.

That was the real king. How did Birbal know who was the real king ?

Find the next number in the series below

21 32 54 87 131 ?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?