UPDATE : POLL RESULTS. Well, nobody voted but I'm giving the answer anyway. It's $80 US.
Here's a good one for you:
How much does it cost for three friends to eat 3 thin-crust 8" pizzas, 3 glasses of fruit juice and 3 triple-scoop ice creams*?
a) $20 US*
b) $50 US
c) $80 US
Please vote in the comments (Will update the blog and have more modern polling when internet access improves)
Results will be posted on Sunday (I hope). Four whole days for you, dear readers, to figure out if x=0, LOL!
* We don't believe in dieting, either!
** The prices are in US not only for convenience but because the US price was printed on the bill.