Help us keep the lights on by shopping at Amazon

Riddles

Talk about anything.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Tue Feb 21, 2017 2:25 pm

People at work have enjoyed my trivia and started writing riddles on the "Tyler's Daily Trivia" board.

When does tomorrow come before yesterday?

Forward I'm heavy; backwards I'm not. What am I?

You have 9 balls. 1 weighs more than the others. What is the minimum ways to use a scale to identify the heavy ball?
User avatar
cwilkins88
Top Contributor
Posts: 2834
Joined: Thu Oct 17, 2013 7:21 pm
Contact:

Riddles

Postby cwilkins88 » Tue Feb 21, 2017 2:35 pm

Tyler wrote:Source of the post People at work have enjoyed my trivia and started writing riddles on the "Tyler's Daily Trivia" board.

When does tomorrow come before yesterday?

Forward I'm heavy; backwards I'm not. What am I?

You have 9 balls. 1 weighs more than the others. What is the minimum ways to use a scale to identify the heavy ball?


1) In a dictionary. If it were for some reason to be asked the other way around, the answer is 'literally always'
2) The word 'ton'
3) let me think on this one.
User avatar
wags83
Moderator
Posts: 9503
Joined: Tue Mar 20, 2012 6:05 pm
Location: Golden Valley, MN
Contact:

Riddles

Postby wags83 » Tue Feb 21, 2017 2:36 pm

Tyler wrote:Source of the post When does yesterday come before tomorrow?

Today?
Tyler wrote:Source of the post Forward I'm heavy; backwards I'm not. What am I?

Ton (I've heard this one before)
Tyler wrote:Source of the post You have 9 balls. 1 weighs more than the others. What is the minimum ways to use a scale to identify the heavy ball?

Weigh 4 balls vs. 4 balls, if they balance then the 9th is the heavy one.
User avatar
cwilkins88
Top Contributor
Posts: 2834
Joined: Thu Oct 17, 2013 7:21 pm
Contact:

Riddles

Postby cwilkins88 » Tue Feb 21, 2017 2:37 pm

3) Put 4 on 1 side and 4 on the other. If they weigh the same, the last ball is it.
If one side weighs more than the other, the side that was heavier should be split 2 and 2. Rinse and repeat with last ball.

It'll either take 1 try or 3.
User avatar
wags83
Moderator
Posts: 9503
Joined: Tue Mar 20, 2012 6:05 pm
Location: Golden Valley, MN
Contact:

Riddles

Postby wags83 » Tue Feb 21, 2017 2:37 pm

cwilkins88 wrote:Source of the post 1) In a dictionary. If it were for some reason to be asked the other way around, the answer is 'literally always'

Ah, must have been a typo, haha. I was trying to make that more complicated than it needed to be.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Tue Feb 21, 2017 2:38 pm

wags83 wrote:Source of the post Weigh 4 balls vs. 4 balls, if they balance then the 9th is the heavy one.

That's what I answered too, but it requires dumb luck for that to happen the first time. There is a way to do it consistently.
cwilkins88 wrote:
Source of the post 3) Put 4 on 1 side and 4 on the other. If they weigh the same, the last ball is it.
If one side weighs more than the other, the side that was heavier should be split 2 and 2. Rinse and repeat with last ball.
It'll either take 1 try or 3.

Nope. There is a better way
User avatar
cwilkins88
Top Contributor
Posts: 2834
Joined: Thu Oct 17, 2013 7:21 pm
Contact:

Riddles

Postby cwilkins88 » Tue Feb 21, 2017 2:41 pm

Tyler wrote:Source of the post Nope. There is a better way


Use a scale made from memory foam. whichever sinks the farthest is the heaviest.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Tue Feb 21, 2017 2:43 pm

cwilkins88 wrote:Source of the post Use a scale made from memory foam. whichever sinks the farthest is the heaviest.

Did you look it up?!?!

► Show Spoiler
User avatar
wags83
Moderator
Posts: 9503
Joined: Tue Mar 20, 2012 6:05 pm
Location: Golden Valley, MN
Contact:

Riddles

Postby wags83 » Tue Feb 21, 2017 3:54 pm

I may have it if this makes sense. You split it into groups of 3. 3 vs 3 either shows you which group is heavier on the scale, or if equal the group not on the scale has the heavy ball. Then weigh 1 vs 1 of the group that has the heavy ball, it either shows which is heavier or if equal shows that the 3rd is heaviest. So always gets you there in 2 tries.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Tue Feb 21, 2017 3:56 pm

wags83 wrote:Source of the post I may have it if this makes sense. You split it into groups of 3. 3 vs 3 either shows you which group is heavier on the scale, or if equal the group not on the scale has the heavy ball. Then weigh 1 vs 1 of the group that has the heavy ball, it either shows which is heavier or if equal shows that the 3rd is heaviest. So always gets you there in 2 tries.

We have a winner!! Kudos if you didn't cheat.
User avatar
wags83
Moderator
Posts: 9503
Joined: Tue Mar 20, 2012 6:05 pm
Location: Golden Valley, MN
Contact:

Riddles

Postby wags83 » Tue Feb 21, 2017 3:59 pm

Tyler wrote:Source of the post
wags83 wrote:Source of the post I may have it if this makes sense. You split it into groups of 3. 3 vs 3 either shows you which group is heavier on the scale, or if equal the group not on the scale has the heavy ball. Then weigh 1 vs 1 of the group that has the heavy ball, it either shows which is heavier or if equal shows that the 3rd is heaviest. So always gets you there in 2 tries.

We have a winner!! Kudos if you didn't cheat.

Wilkins' answer basically got most of the way there, just needed a way to cut out one measurment. Also, I'm a genius.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Wed Feb 22, 2017 2:35 pm

Three boxes - one containing two black marbles, one containing two white marbles, the third containing one black marble and one white marble - are put before you.

The boxes are labeled to indicate their contents - BB, WW and BW - but you are told that the tops have been switched so that every box is now incorrectly labeled.

You are asked to take one marble at a time out of any box, without looking inside, and, using this sampling process, to determine the contents of all three boxes.

What is the smallest number of drawings you will need to determine the contents of each box?

Image
User avatar
bmyoungs
Moderator
Posts: 3987
Joined: Tue Mar 20, 2012 10:20 pm
Contact:

Riddles

Postby bmyoungs » Wed Feb 22, 2017 2:46 pm

2. pull both out of the bw box to determine that box then other two can be solved from that.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Wed Feb 22, 2017 2:49 pm

bmyoungs wrote:Source of the post 2. pull both out of the bw box to determine that box then other two can be solved from that.

You're right on what box to start with, but not for the right reason and your answer is also wrong. Read the question again, there is one specific line that is important.
User avatar
bmyoungs
Moderator
Posts: 3987
Joined: Tue Mar 20, 2012 10:20 pm
Contact:

Riddles

Postby bmyoungs » Wed Feb 22, 2017 3:03 pm

Tyler wrote:
bmyoungs wrote:Source of the post 2. pull both out of the bw box to determine that box then other two can be solved from that.

You're right on what box to start with, but not for the right reason and your answer is also wrong. Read the question again, there is one specific line that is important.

I guess you only have to pull one from that box.

Pull one from box labeled bw since you know it's wrong. You can move correct label to that box and the only box with a label will also be wrong therefore you can swap the remaining two labels and all the are correct.
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Wed Feb 22, 2017 3:11 pm

bmyoungs wrote:Source of the post I guess you only have to pull one from that box.

Pull one from box labeled bw since you know it's wrong. You can move correct label to that box and the only box with a label will also be wrong therefore you can swap the remaining two labels and all the are correct.

You've done it! You only need to pull 1 marble to correctly identify the 3 boxes.
User avatar
wags83
Moderator
Posts: 9503
Joined: Tue Mar 20, 2012 6:05 pm
Location: Golden Valley, MN
Contact:

Riddles

Postby wags83 » Wed Feb 22, 2017 3:48 pm

You're so smart! Everyone's so smart!
User avatar
cwilkins88
Top Contributor
Posts: 2834
Joined: Thu Oct 17, 2013 7:21 pm
Contact:

Riddles

Postby cwilkins88 » Thu Feb 23, 2017 7:44 am

Tyler wrote:
bmyoungs wrote:Source of the post I guess you only have to pull one from that box.

Pull one from box labeled bw since you know it's wrong. You can move correct label to that box and the only box with a label will also be wrong therefore you can swap the remaining two labels and all the are correct.

You've done it! You only need to pull 1 marble to correctly identify the 3 boxes.

I like this thread Tyler. You're stuck with posting on here the rest of your life
User avatar
Tyler
Owner
Posts: 24151
Joined: Tue Mar 20, 2012 9:19 am
Location: Des Moines, IA
Contact:

Riddles

Postby Tyler » Thu Feb 23, 2017 11:34 am

cwilkins88 wrote:Source of the post I like this thread Tyler. You're stuck with posting on here the rest of your life

Well....at least until I change jobs and can no longer copy/paste the riddles asked by teammates.
User avatar
cwilkins88
Top Contributor
Posts: 2834
Joined: Thu Oct 17, 2013 7:21 pm
Contact:

Riddles

Postby cwilkins88 » Thu Feb 23, 2017 3:18 pm

A windowless room contains three identical light fixtures, each containing an identical light bulb or light globe. Each light is connected to one of three switches outside of the room. Each bulb is switched off at present. You are outside the room, and the door is closed. You have one, and only one, opportunity to flip any of the external switches. After this, you can go into the room and look at the lights, but you may not touch the switches again. How can you tell which switch goes to which light?

Return to “Off Topic”

Who is online

Users browsing this forum: No registered users and 5 guests