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?

What is the relationship between these matchstick pictures below?

If 24H in a D => 24 hours in a day.
What does "64S on CB" stand for?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

What does this mean?

CCCCCCC

how come the second man dies?

Using eight eights and addition only, can you make 1000?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Can you find out the number that should replace the question mark with a valid reason?