Three men go to buy a radio. The radio costs €30 They all hand €10 to the salesman who gives it to the cashier. The cashier says, it's been reduced to €25 and gives back €5 to the salesman to give back to the men. The salesman thinks... €5 divided by 3 is tricky, I'll keep €2 and give them back €1 each. So they all paid €9 which makes €27 and the €2 that the salesman kept makes €29. Where's the missing Euro?