the one ring is actually one of twenty rings of power that exist in middle-earth, and its unique ability allows its bearer to control those who wear the other nineteen rings, making the story really about all twenty.
also, at least twelve other rings of power make an appearance in the books. the three greatest rings (that were crafted solely by celebrimbor without sauron's influence) are worn by gandalf, galadriel, and elrond during the events of the story. and the nine rings given to men also show up, as they turned their hosts into the nazgûl, or the ringwraiths, who serve sauron.
"three rings for the elven-kings under the sky,
seven for the dwarf-lords in their halls of stone,
nine for mortal men doomed to die,
one for the dark lord on his dark throne
in the land of mordor where the shadows lie.
one ring to rule them all, one ring to find them,
one ring to bring them all and in the darkness bind them
in the land of mordor where the shadows lie."
if 8/11 pens are blue, then 3/11 are black.
there are 12 black pens, so 12/(3/11) = 44. so there are 44 pens total.
44 * (8/11) tells us that 32 pens are black.
the law of conservation of energy.
a, b, and d.
holidays have large economic impacts. besides the obvious things like people being off of work for the day, sales of turkeys rise dramatically around thanksgiving, and supply chains of all types are regularly stressed at christmas time.
preferences for housing will obviously affect economics, because buying and selling houses, and also building them to begin with, are all economic activity. building and buying houses will be a less significant part of the economy in a society that values renting versus one that values ownership.
what type of music people love won't dramatically affect the economy. it does a little, as people do buy instruments, and the instruments used for popular music will be sold more often than ones that aren't. electric guitars sell more than theremins, for instance, but musical instruments of some variety will generally sell in any place where people listen to music, and the type of music that people listen to is unlikely to affect the rate at which they sell. it may depend on how specific you're being with the word "impact." the impact isn't zero, but it's doubtful that it's significant.
d is somewhat of a sociological assumption, but i believe that it is intended to be included as an answer here. work ethic is generally good for the economy, but whether or not you get it from your parents teaching it to you is more of a social/psychological question than an economic one.
nickels are composed of 75% copper and 25% nickel.