Math Question Help I Dont Get It?
You have 10 stacks of 10 coins each. One stack is counterfeit. A real coin weighs 10 grams, and a counterfeit on weighs 11 grams. All coins look identical. With only one weighing, how can you tell which stack is counterfeit?
The counterfeit will weigh 10 grams more than the real stack?
Take 1 coin from stack 1, 2 coins from stack 2… 10 coins from stack 10. You’ll have a big stack of 55 coins. Weigh that.
Real coins would weigh 550 grams. If the counterfeit stack was stack 1, it will weigh 551 grams. If it was stack 2, it will weigh 552 grams, etc.