I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

What has many keys but can’t open a single lock?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

The more you take me, the more you leave me behind.
Who Am I?

Which Burger Is Different in below image?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

What word begins and ends with an E, but has only one letter?