The Puzzle
A professor brings a bag of 100 coins to her class. She tells the students that some coins are real, and the rest are counterfeit. A real coin weighs exactly 10 grams, while a counterfeit coin weighs 9 grams.
She challenges the class:
“Using a digital scale only once, determine how many counterfeit coins are in the bag.”
Your Task
- Can you figure out the method to identify the number of counterfeit coins?
- What is the minimum number of coins you need to weigh to solve the puzzle?
Think it through carefully and explore all possibilities. Once you’re ready, click the Show Answer button below to reveal the solution and see if you’re right!
