80 from store 1 = $4
1 from store 2 = $1
19 from store 3 = $95

Your right elbow. You can try it yourself if you’re not convinced, but unless you have a broken arm or an incredibly flexible ulna, you won’t reach it.

He hung the hat up on his gun.

The most popular answer for this teaser is ‘today’. Of course this only works if you’re reading it on that particular date or if the date is not specified. Another option is to respond literally with ‘a date’. Lastly, certain dates could be squeezed into letters using Roman numerals if you abbreviate the year to 2 numerals. For example, January 20th, 2011 would be I XX XI.

Only once. The next time you’d be subtracting 10 from 90.

After shooting a quarter of the birds, the rest would fly off, so the remaining birds, brutally shot by you, would be:

(2 × (4 + 20)) / 4 = 12