# Counterfeit gold coins Riddle | Don't Memorise | Summary and Q&A

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December 27, 2020
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Infinity Learn NEET
Counterfeit gold coins Riddle | Don't Memorise

## TL;DR

Zeki uses a strategic approach to solve a puzzle involving 10 bags of gold coins with one bag containing defective coins, ultimately securing his place in a competition.

## Key Insights

• 🥖 The puzzle involves 10 bags of gold coins, with one bag containing counterfeit coins that weigh 9 grams instead of 10 grams.
• 🏋️ Zeki's strategy involves assuming a small sample of bags, removing an unequal number of coins from each bag, and using the weighing machine to determine the total weight.
• 🥖 By applying this strategy to the 10 bags, Zeki can identify the bag with counterfeit coins by using the least number of bags.

## Transcript

zeki is selected from his college to participate in an intercollegiate personality competition this screening round for this competition is logical reasoning zeki and his opponents have to solve a puzzle given to them in this screening round to enter the competition let's first look at the puzzle there are 10 bags of gold coins each bag contains 10... Read More

### Q: How does Zeki approach the puzzle involving the 10 bags of gold coins?

Zeki begins by assuming a sample of three bags and removing a different number of coins from each bag. He then uses the weighing machine to determine the total weight, allowing him to identify the bag with counterfeit coins.

### Q: Why does Zeki remove an unequal number of coins from each bag?

Zeki realizes that if he were to remove an equal number of coins from each bag, the total weight would always be 60 grams, regardless of whether any bags contain counterfeit coins. By selecting an unequal number of coins, he can identify the bag with the defective coins based on the difference in total weight.

### Q: What strategy does Zeki use to solve the puzzle with the 10 bags of gold coins?

Zeki divides the bags into two sets, with nine bags in one set and one bag in the other. He applies the strategy he used for the sample of three bags to the set of nine bags, allowing him to identify the bag with counterfeit coins. If the weighing machine displays the weight as 450 grams, he knows that the tenth bag contains the defective coins.

### Q: Why does Zeki choose the ratio of nine is to one in dividing the bags?

By dividing the bags into the ratio of nine is to one, Zeki ensures that he can determine the bag with counterfeit coins without using the weighing machine a second time. This ratio provides an optimal solution, guaranteeing his place in the competition.

## Summary & Key Takeaways

• Zeki is selected for an intercollegiate personality competition where participants must solve a puzzle involving 10 bags of gold coins, one of which contains counterfeit coins that weigh 9 grams instead of 10 grams.

• Zeki's strategy involves assuming a sample of three bags, removing a different number of coins from each bag, and using the weighing machine to determine the total weight. Through this process, he can identify which bag contains the defective coins.

• By applying this strategy to the 10 bags, Zeki successfully finds the bag with counterfeit coins by using the least number of bags, securing his place in the competition.