18
Got the merry-go-round right, but not the fan. (The merry-go-round one is trivia from living in Portland, there is(was?) a Burger King with one that turned the wrong way, and a plaque explaining how that was rare.
Lugnuts one was dumb. Got it right anyway, but it's by no means a standard. Any number from 3 to 8 would be acceptable for road legal non-commercial vehicles. (Edit: and 1 nut of course)
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"I would rather be exposed to the inconveniences attending too much liberty, than those attending too small a degree of it." - Thomas Jefferson