Riddle me this!

[livingart]

that is correct if you know the coin is lighter or heavier

but you don't know that

threw me out too P44

[Scottie841]

I would devide in to 3 groups of 4 and weigh 2 them. I am a lucky guy so the 2 would be the same limiting it to 4 coins left I would then weigh 2 of the coins and 2 of the ones we already know are the same. If these are the same I know one of the 2 in my hand is the odd one (of if different the ones on the scales). I would then for my 3rd weight place one of the coins on the scales keep one in my hand and put one of the known coins on the scales and if it is different you have the culprit and if the same then the one is in my hand is the odd one.

Am I right?

[bdspider]

Pretty good Scottie, but what if you don't get lucky? eg if it were me weighing the coins :evil: You can have half a mark I guess.

Yeah Phoenix, you're completely off due to the reasons LA gave.

[livingart]

float a coin on a piece of polystyrene and mark the line it sits at

then do same with rest of coins to determine odd one out

throw away the scales

[Scottie841]

:evil: You can have half a mark I guess.

Does half a mark mean that I get to ask half a riddle?

but what if you don't get lucky

If I had the 8 coins and one of them was different how could I find that one by only weighing them twice?

[bdspider]

So, the riddle is half solved by Scottie, as in we know how to find the odd coin if it's in the un-weighed pile after the 1st try.

So now, how do you tell the odd-coin from 8 other coins? Keep in mind you now have 4 coins which must all weigh the same (the 3rd, unweighed pile)

2 balances left.

[Tsarmina]

if its in the unweighed pile:

you take 2 coins from the unweighed pile and 2 coins from a weighed pile

if they are unbalanced, the coin is on the scales. if it is balanced, the coin hasn't yet been weighed.

you then take 1 of the coins from the relevant group from the above weighing and 1 of the coins that has been weighed.

if they are unbalanced, you have your coin on the scale

if they are balanced, the coin is the remaining one that hasn't been weighed yet

[bdspider]

if its in the unweighed pile:

you take 2 coins from the unweighed pile and 2 coins from a weighed pile

if they are unbalanced, the coin is on the scales. if it is balanced, the coin hasn't yet been weighed.

you then take 1 of the coins from the relevant group from the above weighing and 1 of the coins that has been weighed.

if they are unbalanced, you have your coin on the scale

if they are balanced, the coin is the remaining one that hasn't been weighed yet

Yup, that's what Scottie already solved Now we want to know, what if when you weigh the first 8 coins, the scales don't balance? How do you then find the off coin from those 8? 2 more weighings.

[elusive_fish]

OK, so if the solution so far is correct... 3 groups of 4 coins.

TRIAL 1:

Weigh group 1 against group 2.

If balanced, the odd coin out is in Group 3

If they are not balanced:

TRIAL 2:

weigh group 1 against group 3

If group 1 was heavier in trial 1, but balanced in trial 2 then the odd coin must be light and in group 2

If group 1 was lighter in trial 1, but balanced in trial 2 then the odd coin must be heavy and in group 2

If group 1 was lighter in trial 1 and also trial 2 then the odd coin must be light and in group 1

If group 1 was heavier in trial 1 and also in trial 2 then the odd coin is heavy and in group 1

If group 1 was balanced in trial 1 and heavier in trial 2 then the odd coin is light and in group 3

If group 1 was balanced in trial 1 and lighter in trial 2 then the odd coin is heavy and in group 3

Here is where I'm stuck...

TRIAL 3

Divide the suspect group in 2. Depending on whether the odd coin is lighter or heavier as determined by trial 2 you can tell within two coins which is the dodgy one.

OR

Put one coin each of the suspect pile on the balance. If they are balanced... damn. If not, you have your coin!

[phoenix44]

I takes my wand. wingardium leviosa. *

fastest one up is lightest. slowest one up is heaviest.

i need no scales.

*points wand

[Tsarmina]

i couldn't work it out, so i cheated (but i won't post the answer in case someone can work it out) :lol:

[Scottie841]

i couldn't work it out, so i cheated (but i won't post the answer in case someone can work it out) :lol:

I think we are all stuck so can you pllease tell us and we can start another riddle

[bdspider]

I'll post this googled explanation cos I'm bad at explaining it:

Number the coins from 1 to 12.

Weighing # 1:

Weigh coins 1-4 against coins 5-8.

If the coins don't balance , go to Weighing #2A, below.

Weighing #2:

If the coins balanced in the first weighing, the counterfeit is one of coins 9-12. Weigh coins 9,10, and 11 against coins 1, 2 and 3. If the 9,10,11 side goes down (or up) then the counterfeit coin is 9,10 or 11 and depending on whether the scale goes up or down, you know whether the coin is heavy or light. If the scale tipped out of balance, weigh coin 9 against coin 10. If coins 9 and 10 weigh the same, the counterfeit is coin 11. Otherwise the

counterfeit coin is the coin that tips the scale in the same direction as coins 9,10,11 did in the second weighing. However, if the 9,10,11 coins balanced with the 1,2,3 coins, the

counterfeit coin is #12.

Weighing #2A: (The coins did not balance in weighing #1)

If coins 1,2,3,4 didn't balance with coins 5,6,7,8, remember whether coins 1-4 were heavier or lighter than the other coins. Take coins 1,5,6 and 7 and weigh against coins 8,9,10 and 11. If coins 1,5,6,7 go in the same direction as coins 1-4 in the previous weighing, the counterfeit is coin 1 or coin 8. In that case, weigh coin 1 against coin 12. If they balance, the counterfeit coin is coin 8, otherwise the counterfeit is coin 1.

If coins 1,5,6,7 tip the scale in the opposite direction as coins 1-4 did earlier, this eliminates coins 1,2,3,4,8,9,10,11 and 12. The counterfeit is coin 5,6 or 7. Weigh coin 5 against coin 6.

If they balance, Coin 7 is the counterfeit. Otherwise, the counterfeit coin is the one that tips the scale in the same direction as the coins 1,5,6,7 tipped in the prior weighing.

If coins 1,5,6,7 balance with coins 8,9,10,11, balance coins 2 and 3. If they balance, the counterfeit coin is coin 4. Otherwise the coin which tips the scale in the same direction coins (1-4) did in the first weighing, is the counterfeit.

[bdspider]

I wanna do an easy one to get us going, hope noone minds:

A man lives on the 22nd story of an apartment building. When it has been raining or if there is someone else in the lift, he goes straight to his home floor on the lift.

But when it's fine and he's alone, he only goes to level 18 on the lift and then walks the rest of the way up the stairs.

Why?

[Tsarmina]

he was too short to reach the button to his floor in the lift, but on rainy days he would have an umbrella to push the button with :lol:

if a man carried my burden

he would break his back

i am not big

but leave silver in my tracks

what am i?

[bdspider]

First 3 lines make me think ant... Last one makes me think spider.

No wait! Snail!

[Tsarmina]

First 3 lines make me think ant... Last one makes me think spider.

No wait! Snail!

yep

[bdspider]

Different lights do make me strange, thus into different sizes I will change. What am I?

[nightwlf]

a pupil?

[bdspider]

Yup

[nightwlf]

There are 5 houses that are each a different colour. There is a person of a different nationality in each house. The 5 owners drink a certain drink. They each smoke a certain brand of cigarettes and also have a certain pet. No owner has the same pet, smokes the same brand of cigarettes nor drinks the same drink. The question is. “Who has the fish?”

CLUES

1. The British man lives in the red house.

2. The Swedish man has a dog for a pet.

3. The Danish man drinks tea.

4. The green house is to the left of the white house.

5. The owner of the green house drinks coffee.

6. The person that smokes Pall Mall has a bird.

7. The owner of the yellow house smokes Dunhill.

8. The person that lives in the middle house drinks milk.

9. The Norwegian lives in the first house.

10. The person that smokes Blend, lives next to the one that has a cat.

11. The person that has a horse lives next to the one that smokes Dunhill.

12. The one that smokes Bluemaster drinks beer.

13. The German smokes Prince.

14. The Norwegian lives next to a blue house.

15. The person that smokes Blend, has a neighbour that drinks water.

[Tsarmina]

this is a very old riddle that has been done here before

[nightwlf]

ehhhh okay. i suppose i should've read the thread carefully.

and still should've... if this one's already been done, then whoever posts next can have the riddle lol.

A man and his son were out driving when they got into a car accident. On the way to the hospital in the ambulance, the man perishes. When the boy is rushed into theater, the surgeon says 'I cannot operate on this boy, he is my son.'

How is this possible?

[bdspider]

this is a very old riddle that has been done here before

Eh? I haven't seen it & I follow this thread obsessively. Although it is a logic puzzle, not really a riddle. & I can't be bothered working it out, so carry on.

[Scottie841]

ehhhh okay. i suppose i should've read the thread carefully.

and still should've... if this one's already been done, then whoever posts next can have the riddle lol.

A man and his son were out driving when they got into a car accident. On the way to the hospital in the ambulance, the man perishes. When the boy is rushed into theater, the surgeon says 'I cannot operate on this boy, he is my son.'

How is this possible?

It is his mother.

Again I dont have anything to ask so the next next person to post can have it