# Interesting logic puzzles and brain teasers

• vette982
In summary: Thanks for coming up with the solution.Yes, I did think of it, and thanks, but no, I don't think it's anything special.
vette982
I thought it would be cool to start a thread with a bunch of interesting logic puzzles, brain teasers, math problems, etc. I'll get the ball rolling:

Your pharmacist gives you 5 jars filled with pills. The pills contained in each jar have an identical appearance and size (i.e. if you mixed all of the pills you wouldn't be able to tell them apart).

4 of the 5 jars hold pills that weigh 10 grams each, and the remaining jar holds pills that weigh 9 grams each. However, you don't know which jar is the one holding the lightweight pills. Keep in mind that all of the pills in all jars are identical in appearance and size.

You are given a weighing scale that can only be used once. Using this scale (only once), how do you determine which jar is holding the 9 gram pills?

Note: assume the jars are quite large and that you have an unlimited quantity of pills from each jar.

Solution: http://www.mindcipher.com/puzzles/141

I'm not sure if this counts, because I would consider it using the scale more than once. But I would put 1 pill from each jar onto the scale, and then take them off one by one. When you take off a pill and the reading is an even number, you know you took off the 9 gram pill.

Note that there's already a "Brain Teasers" subforum of "Fun, Photos and Games", so perhaps this subject belongs there:

https://www.physicsforums.com/forumdisplay.php?f=33

vette982 said:
I thought it would be cool to start a thread with a bunch of interesting logic puzzles, brain teasers, math problems, etc. I'll get the ball rolling:
Solution: http://www.mindcipher.com/puzzles/141

This belongs in the brainteaser thread.

Anyway, the solution is quite trivial.

SPOILER (white text):

Label the jars 1 to 5. Take 9,8,7,6,5 pills from each jar respectively. The last digit of the weight will indicate which jar it is.

EDIT: just saw the solution you linked, and honestly, I think mine's neater (posted it there as a comment).

Last edited:

Curious3141 said:
EDIT: just saw the solution you linked, and honestly, I think mine's neater (posted it there as a comment).

Did you think of that? Because that's pretty genius.

Yeah that's a super clean solution!

leroyjenkens said:
Did you think of that? Because that's pretty genius.

Yes, I did think of it, and thanks, but no, I don't think it's anything special.

## 1. What are logic puzzles and brain teasers?

Logic puzzles and brain teasers are types of games or problems that require critical thinking and reasoning skills to solve. They often involve a set of clues or information that must be analyzed and organized in order to find the solution.

## 2. What is the purpose of solving logic puzzles and brain teasers?

The purpose of solving these types of puzzles is to exercise and improve cognitive skills such as problem-solving, logical reasoning, and creative thinking. They also provide a fun and challenging way to pass the time.

## 3. Are there different types of logic puzzles and brain teasers?

Yes, there are many different types of logic puzzles and brain teasers, including riddles, number puzzles, spatial puzzles, and lateral thinking puzzles. Each type requires a different approach to solve.

## 4. Can solving logic puzzles and brain teasers improve intelligence?

While there is no definitive answer, many people believe that regularly engaging in activities that challenge the brain can improve cognitive abilities. Solving logic puzzles and brain teasers may help improve problem-solving skills and critical thinking abilities.

## 5. Where can I find interesting logic puzzles and brain teasers?

There are many resources available for finding logic puzzles and brain teasers, including books, websites, and mobile apps. You can also create your own puzzles or participate in puzzle-solving groups or competitions.

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