There are 4 bottles of pills each having 100 pills inside of them. One bottle of pills is poisoned. A pill that is good weighs 1 kilogram. The poisoned ones weigh exactly 1.1 kilograms. A scale can be used to measure the weight of the pills, but it can only be used once. How can you determine which bottle has the poisoned pills?
2007-02-07 07:10:04 · 4 answers · asked by Kathy B 1 in Science & Mathematics ➔ Other - Science
Put one of each kind of pill on the scales then remove one at a time noting the difference. Alternatively do the same with the bottles, if you do not want to open them before hand.
2007-02-07 07:21:13 · answer #1 · answered by Kirstin 2 · 2⤊ 0⤋
It's kind of cheating, but this may be the solution.
Let's say that out of bottles A, B, C and D, that C is the poisoned one.
Put any two bottles, AB one one side and CD on the other. Obviously, the side with bottle C (the poisoned one) is heavier, so it sinks down on the scale.
Once you've done this, take a bottle away from each side, noting which side the poisoned bottle was on. Iin our case, this was the side with CD. If you take away C, the poisoned bottle, the scale will return to balanced and you know you're holding the poisoned bottle. If you take away D, the unpoisoned bottle, the scale will still be unbalanced and the poisoned bottle, C, will still be on the scale.
It's a little bit of a stretch, since you used the scale with two measurements. But since your second measurement was just an extention of the first measurement, you could say you were only "using" the scale once.
2007-02-07 15:27:21 · answer #2 · answered by Pythagoras 7 · 0⤊ 1⤋
Take 1 pill out of 3 of the bottles (Make sure you know which pill came out of which bottle) and weigh them. If it weighs exactly 3 kilograms then you know the bottle that did not have a pill taken out is poisoned. If it weighs 3.1 kilograms then you know that one of the 3 measured is poisoned and that the bottle not measured is not. So use that one and throw away the others :)
2007-02-07 15:25:19 · answer #3 · answered by John 1 · 1⤊ 0⤋
Take one and if you dont die then it isnt poisoned if you take one and you die then you took the poisoned one.
2007-02-07 15:19:03 · answer #4 · answered by Jason F 2 · 0⤊ 1⤋