I look at you, you look at me, I raise my right, you raise your left. What am I?

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

Can you find out which options fits best with the missing column?

What kind of band never plays music?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?