Math riddles and brain teasers with numbers. This math is not boring!

# Maths puzzles and Number Riddles

## Boxes with marbles

You have three boxes full of marbles. There are stickers saying “white” “red” “red and white” on them indicating what color are the marbles inside the boxes.

One day someone moves the stickers so that none of them is on a correct box. How many marbles do you have to draw to place all stickers correctly again without looking inside the boxes?

## Dad

Mom is 21 years older than her son.

In 6 years she will be 5 times older than her son.

Where is the father right now?

## Heads – tails

As it often happens in life evil warlock imprisoned a wise man. Surprisingly he gave him a chance to save himself if he fulfils one task.

There is a round tray on the table which can be turned around freely. There are four coins on the tray placed as corners of a square.

Wiseman has his eyes covered so he doesn’t see anything. His task is to turn the coins so that they are all heads up.

He is not in easy situation. He may turn some coins and than the warlock will turn the tray around. He turns some coins again warlock turns the tray again. It goes on until all coins are turned correctly. At that moment evil warlock ends the game.

Wiseman can’t recognize one side from the other by touching it. He has to leave the coins where they were in the corners of a square. And mainly – because of the evil magic – he has the worst luck so if he relies just on chance he will never fulfill the task.

## Justice

Parents buy cookies for their kids. They are saving money so they buy two discounted ones (few days after best before). They don’t want to look greedy so they also buy two cookies for the full price.

When they come home their two kids grab cookies, and each get two. They don’t check best before so their choice is random.

Do you think that life is fair and each kid gets one expired and one good cookie? Or one kid gets both expired? What is more likely to happen?

## Lords

Three lords enter a hotel. The receptionist at the front desk tells them that one room is 10 pounds so each of the gentlemen pay – 30 pounds altogether.

When the porter wants to bring the luggage to lord’s rooms, hotel director rushes in to tell him that it was supposed to be only 25 pounds for the three rooms and he gives him the extra 5 pounds to return them to lords.

The porter had no idea know how to divide 5 pounds between 3 gentlemen so he gave one pound to each of them and kept the remaining 2.

Each lord paid 9 pounds (10 originally and got one back). 3x9=27. The porter kept two pounds. 27+2=29. What happened with the remaining one pound?