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Bottle, Burger, Beer, Hot Dog Viral Puzzle – Mind Your Decisions
(mindyourdecisions.com)
"As viral puzzles became popular, mathematicians joined the game too. Here’s a fun puzzle that has been widely shared."
I don’t think that would work. You just use the fact that the integral from negative to positive infinity of sin(x)/x is pi, so from 0 to infinity it is pi/2, which you can derive from using Feynman’s trick for computing weird integrals like these.
Ah, that's the trick I was missing. Thx!