Alright...this was given to a class of MBA students who couldn't
figure this out. The answer should be recognizable. It follows a
format like this:

26=L of the A  The answer is 26 letters of the alphabet
88=PK The answer is piano keys
4=Q in a G The answer is quarters in a game.

Alright...here is the one we couldn't figure out...

3=L in a PC

I couldn't figure it out, however, if it was 3=L in a HP, it would be
3 Lines in a Haiku Poem.

Best of luck,
Rainbow

maybe its:

3 liquors in a perfect cocktail

perfect cocktail - a cocktail consisting of equal parts of French
vermouth, Italian vermouth, and gin shaken with ice and strained
before serving

technically vermouth is wine soooo maybe not.  but thats the best i can muster

Three letters in a postal code.
Works for some parts of London and other big cities.

I don't know your answer either, but while it is understandable that
all of those MBA's would think of "quarters" and "games" I
respectfully submit that the 4=Q in a G should be 4 quarts in a
gallon.

nkamom is right...
4=Q is 4 quarts to a gallon.

And I agree with dufasmcwarne... 
The correct answer is 3 letters in a postal code. Here in Canada, our
postal codes consist of 3 letters and 3 numbers.

Steph53

3 lights in a patrol car (?)
(red, blue, white)

the 4 quarts in a gallon v. 4 quarters in a game split pretty evenly
in the class down gender lines in the class...

given:

3=L in a PC 

and given JABO (just another bunch of MBAs)

could it be

3 equals the number of labeled axes (Laxis) on a Pareto Chart

http://www.isixsigma.com/library/content/c010527a.asp

@Rainbow - is a Haiku not 17 syllables ?

I'm not sure about this one, but there are 3 Levels in a Pullman Car

3 lawyers in a public court
             a privy council

3 ladies/lasses/lads/lords/Londoners in a pony cart

3 lawmen in a police car (thanks Darrel)

3 libertines in a Parisian cathouse

3 locals in a pub chatting

3 lads in a p..ing contest

3 lessons in a personal conversation (:  listen, listen, listen)

3 listeners in a public concert

3 l...?    but that all doesn't fulfill the logical consequence of the
other examples ...  Frde-ga, 17 sylables in 3 lines; only 2 levels in
a Pullman car.

Just a thought..... How do we know when we have got it correct?

And while I'm here,
3 layers in a party cake
3 lengths in a pool cue

but i still think its 3 letters in a postal code.

Eureka!  I got it!

"Ha, ha, ha"; 3 laughs in a poor comedy.

From: http://www.answers.com/topic/passenger-car-1

<q>
First conceived by George Pullman in the late 1850s, the Pullman car
originally was designed to resemble a coach during the daytime with
fold-out beds and privacy curtains for night time. The beds were
located on each side of the car, in up to three levels. Passengers
used portable ladders to access the upper berths.
</q>

Hence my guess ...