Self-tutoring about financial math: the tutor mentions the mortgage interest rate. I was looking at the formula for the periodic payment of a mortgage: P=(-1(r/n))*L*(1+r/n)^(nt)/(1-(1+r/n)^(nt)) where P=payment r=rate n=payments per year (and compounding periods per year as well) t=years Specifically …
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Self-tutoring about Iraq: the tutor mentions its northern, eastern, and southern borders. Iraq is “mostly broad plains” (cia.gov), with mountains to the north (border with Turkey) and east (Iran). Its extreme southeastern border with Iran, starting from about 10 km …
Self-tutoring about two of the most prominent rivers in human history: the tutor mentions the Tigris and Euphrates. Some interesting facts about the Tigris and Euphrates I learned today: They both begin in Turkey. They flow generally southeast, roughly parallel …
Self-tutoring about “backstabbing”: the tutor relates its meaning in household wiring. Some electrical outlets have holes in the back that can receive incoming wires from the household wiring system. Such a hole contains a clamp that holds the wire once …
Self-tutoring about the past and people from it: the tutor recalls Colleen. To begin this story, here are some facts: Her name wasn’t Colleen: to protect the the innocent, no-one’s real name is used in this account. This story doesn’t …
Self-tutoring about observations in the night sky: the tutor mentions one. For months I’ve been noticing a red body in the night sky. Now, with darkness around 5pm, the body is evident earlier. I can’t be sure when it’s central …
Self-tutoring about river words: the tutor mentions distributary. A distributary is a channel that breaks from the main river to reach its own, separate destination. Source: nationalgeographic.org bitannica.com
Self-tutoring about mammals: the tutor mentions the Atlas bear. The Atlas bear lived in the Atlas Mountains of North Africa, and perhaps further east as well. It was around the size of a black bear, but heavier: 450 pounds may …
Self-tutoring about the coming vaccination for Covid-19: the tutor mentions a few interesting bits about it. Apparently, the first doses of the Covid-19 vaccine will be given, possibly, before year-end in the US. In Canada, the vaccinations are expected to …
Self-tutoring about weather: the tutor looks into the difference between sleet and freezing rain. Both sleet and freezing rain result from liquid raindrops originating in a layer of warm air, then falling into a layer of cold. If they freeze …