38 replies to this topic

[rookie1ja]

Bavarian - Back to the Logic Puzzles
One glass has 10 cl of tonic water and another 10 cl of fernet. Pour 3 cl of tonic into the glass with fernet and after mixing thoroughly, pour 3 cl of the mixture back into the glass with tonic water.
Is there more tonic in the glass of fernet or more fernet in the glass of tonic?
(Ignore the chemical composition!)

This old topic is locked since it was answered many times. You can check solution in the Spoiler below.
Pls visit New Puzzles section to see always fresh brain teasers.

Spoiler for Solution

Bavarian - solution
There is exactly as much tonic in the glass of fernet as there is fernet in the glass of tonic.

Spoiler for old wording

Having 2 glasses, in one is 10 cl of tonic and in the other 10 cl of fernet. Pour 3 cl of tonic to the glass with fernet and after thorough mixing pour 3 cl of the mixture back to the glass with the tonic. Is there now more tonic in the glass of fernet or more fernet in the glass of tonic?
(Ignore chemical composition!)

[Detra]

The math is interesting; when you place the the 3 cl of tonic into the glass of fernet the glass now contains 3/13 parts tonic. Assuming that the tonic is mixed evenly throughout, when you take the 3cl the second time, 10/13 of it is fernent, which is approximatly 2.3 cl. The remaining tonic in the fernent is 10/13 of the 10 cl, which is approximatly 2.3 cl as well.

[ryan__]

whaaaa

[AyD3n]

it works for any amount... if x amount of tonic goes into the fernet, obviously x amount of fernet has to go into the tonic (where else it is supposed to go?), so that both still has 10cl.

[haleythebuddha]

[u][u]This made my brain hurt.

Literally, there are veins popping out of my head.

[Garrek99]

Here is another way of looking at it:

When you bring back 3 cl of whatever the name of that drink is you are actually bringing back 2.3 of ferxxx and 0.7 tonic.

So in the end you get 7.7 tonic to the 2.3 fernxxx and in the other glass you are left with 2.3 of the original 3.0 tonic (3.0-0.7) plus the 10-2.3 (frenxxx that went back to the tonic glass) 7.7 fernxxx = 10.0.

[Numenor]

umm... I did it differently... Is this still correct?

After pouring the 3cl of tonic into the fernet, there would be 3/13 tonic and 10/13 fernet in the fernet glass (with 7/7 in the tonic glass).
When you pour the 3 cl back, you would get 1.5 cl of tonic and 1.5 cl of fernet (since they were mixed thoroughly).
That leaves 8.5/10 tonic and 1.5/10 in the tonic glass, and 1.5 tonic and 8.5 fernet in the fernet glass.

That comes with the same answer, but did I do it wrong and was just lucky, or what?

[Garrek99]

umm... I did it differently... Is this still correct?

After pouring the 3cl of tonic into the fernet, there would be 3/13 tonic and 10/13 fernet in the fernet glass (with 7/7 in the tonic glass).
When you pour the 3 cl back, you would get 1.5 cl of tonic and 1.5 cl of fernet (since they were mixed thoroughly).
That leaves 8.5/10 tonic and 1.5/10 in the tonic glass, and 1.5 tonic and 8.5 fernet in the fernet glass.

That comes with the same answer, but did I do it wrong and was just lucky, or what?

Neah bro. Here is what I see wrong with the math:
When you pour back 3 cl you are pouring back 3* 3/13 =0.7 tonic + 3* 10/13 =2.3 fernet = 3.0 cl and not 1.5 & 1.5. You see what I mean. So, you end up with 7.7 & 7.7 not 8.5 & 8.5.

[Numenor]

Neah bro. Here is what I see wrong with the math:
When you pour back 3 cl you are pouring back 3* 3/13 =0.7 tonic + 3* 10/13 =2.3 fernet = 3.0 cl and not 1.5 & 1.5. You see what I mean. So, you end up with 7.7 & 7.7 not 8.5 & 8.5.

Ok, I see where I messed up now. I must have been thinking they were equal or something...

[riddler]

this is getting to complicated. I may be wrong here but it seems to me that there would not be more in either glass. If the mix was even, the amounts of tonic and fernet must be even as well. No calculations need....