It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Can you count the number of quadrilaterals in the picture below?

What do you think with the below Picture ?

To attend world science seminar, A famous chemist from Mexico visit
London. In the lab, the scientist was killed and his six assistants were under suspicion of killing the chemist.
Name of six assistants: Austin, Wayne, Dege, Oscaru, Lingard, and Rojo.
He left a note "76-20-44 79-16-22-7"

A local detective Jack was called to solve the case,

After reading the note, Jack instantly asked the police to arrest the murderers.

Who are the murderers?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Find the last number in the series below:

voN luJ yaM raM ---

I inserted a coin in a bottle and closed its mouth with the help of a cork. Now, I was able to take the coin out from the bottle without taking out the cork or breaking the bottle. Can you tell me how I did it?

An ant is travelling on a 1-meter-long rope at 1 cm/second but also the entire rope is being stretched by an extra 1 meter/second. Is it possible for the ant to reach at the end of the rope?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

Why do we preferably have round manhole covers and not square ones?