Can you find out the missing number in the grid?

How can you tell a raw egg from a hard-boiled egg?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

A bomb exploded in a room full of married couples and no one died. How?

Can you find the thief by just looking at the picture below?