Rs 500 Note Puzzle | Puzzles for Interview - Interview Preparation PDF Download

Introduction

A puzzle that involves a transaction between a lady, a shopkeeper, and another shopkeeper has been making rounds on the internet. In this puzzle, the shopkeeper has to find out how much money he lost in the whole process.

The Puzzle

A lady bought an item worth Rs 100 from the shopkeeper and paid him through a Rs 500 note. However, the shopkeeper did not have change and had to get it from another shopkeeper. He paid Rs 400 to the lady and kept the remaining Rs 100 in his transaction box. After a few days, the other shopkeeper realized that the note was fake and took back the Rs 500 note from the shopkeeper.

Solution

To solve this puzzle, we need to understand the transaction that took place. The lady gave the shopkeeper a counterfeit Rs 500 note which is of no value. The cost of the item she bought was Rs 100, and the shopkeeper gave her Rs 400 as change. Therefore, the total transaction value was Rs 500.
As the Rs 500 note turned out to be fake, the other shopkeeper took back the same amount. This means that the total loss was incurred by the shopkeeper who gave Rs 400 as change to the lady. Hence, the shopkeeper lost Rs 500 in this whole process.

Conclusion

This puzzle is an excellent example of how a small mistake can lead to significant losses. Shopkeepers should always be careful while accepting currency notes and should have a counterfeit detector machine to avoid such situations.