FILE No.173Unsolved
There are ten bottles of medicine. Nine contain pills of 1 g each, and one contains pills of 2 g each. Every bottle holds plenty of pills.
Using an accurate scale, you want to find the bottle containing the 2 g pills.
What is the fewest number of times you need to use the scale?
If you get stuck, open the hints one at a time, in order.
Can you change the number of pills you take from each bottle?
What would the total be if all were 1 g?
The clue is how many grams off the weight is.
What is the fewest number of times you need to use the scale?
Choose the answer closest to the truth.
1 time
The answer is "1 time."
Take 1 pill from bottle 1, 2 pills from bottle 2, and so on, up to 10 pills from bottle 10, and weigh them all together. If all were 1 g, it would be 55 g.
If the 2 g bottle is number 3, the 3 pills weigh 3 g extra, making 58 g. The extra amount is exactly the bottle's number.
Because you think of weighing the bottles one at a time.
The cases on this site are fictional puzzles created for entertainment. Any resemblance to real people, organizations or events is coincidental.
© Unsolved Files
