## 197. Math Puzzle 10/81

"So far, you have received 6 Marks as pocket money. From now on, you will only get 0.8 of this pocket money!", said the father. Jörg was initially upset, but then he happily gave his little sister Claudia a bag of candy.

How can Jörg's behavior be explained?
First, Jörg was angry because he thought he would receive less than 6.00 Marks as pocket money. Upon recalculating, he realized he had been mistaken, because:

$6.00 : 0.8 = 60 : 8 = 7.5$

So, he would receive 7.50 Marks as pocket money in the future. No wonder he was happy.