This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

What does does this rebus picture means ?

If an electric train is travelling south, then which way is the smoke going?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

What is the centre of gravity?

Solve the mathematical equation in the picture below.

Look at the picture and find out which square is not linked with any of the other squares.

Count the number of triangles in the picture below:

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.
How many people have guessed three fruits correctly, and how many people have guessed four fruits correctly

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