Find the hidden tiger in the given optical illusion ?

Can you count the number of squares in the figure below?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Can you start the fire using two pieces of wood?

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

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

Solve the rebus riddle in the picture below.

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

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?