A man plots the murder of his wife. His plan is full proof. Nobody saw them leaving their house. He stabbed her with a knife while driving. She died on the spot. He threw her body in a valley. He threw the knife carefully wiping his finger prints on a random garbage bin. Then he went back to his home and no one was watching him this time as well.

After an hour, he was called by the local police department who informed him that his wife was murdered. They asked him to reach the scene of crime immediately. But as soon as he arrived at the crime scene, he was arrested by them.

How did the police know that he himself is the murderer?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

Remove two matchsticks to make the below equation correct.

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?