Recent Calculations

Latest calculations from the blog

Buy New, Buy Used, or Lease an Elantra for 5 Years? — What the Lease's $2,000 Premium Actually Buys
Money & Economy · Everyday Life

Buy New, Buy Used, or Lease an Elantra for 5 Years? — What the Lease's $2,000 Premium Actually Buys

How much does the same Hyundai Elantra (the Avante in Korea) really cost over five years — bought new, bought as a 3-year-old used car, or on a 60-month long-term rental? This piece breaks down exactly what the lease's ₩49,021 (≈$34) monthly premium over buying new actually buys — depreciation uncertainty, breakdown risk, upfront capital — and finds the new-vs-used race, a ₩1.27M gap in cash terms, closes to a mere ₩9,193 once real financing rates enter the picture.

#car TCO#new vs used car#car lease#car depreciation#auto financing
If You Guessed Every Answer on Korea's CSAT, What Score Would You Get?
Everyday Life · Society & Law

If You Guessed Every Answer on Korea's CSAT, What Score Would You Get?

Guess your way through all 45 questions on the Korean-language section of Korea's CSAT and the math says you'll land near 20 points, with a standard deviation of 6.07. But the odds of a flat zero sit in the exact same statistical neighborhood as the odds of scoring 47 or higher. The probability of a perfect 100 is 3.52×10⁻³² — 8,158 times the age of the universe, even with 8 billion people guessing once a second. The twist: that terrible probability comes from question count, not difficulty, until real perfect-scorer data reveals the actual culprit is a handful of killer questions. Run the same math on the redesigned ACT and the odds get even more absurd.

#CSAT#SAT#ACT#probability#expected value#guessing
Can You Measure Faith in Joules? Marching Around Jericho 13 Times
Physics & Science

Can You Measure Faith in Joules? Marching Around Jericho 13 Times

The Book of Joshua describes six days of marching once around Jericho's walls, then seven laps on the seventh — 13 laps in all. How far did that add up to for one person, how long did it take, and how much metabolic energy did 40,000 marchers burn doing it? We reverse-engineer the city's size from archaeology, weigh three guesses at how far back from the wall they actually walked, and convert the total into joules — and, just for scale, into tons of TNT.

#Jericho#faith and physics#energy expenditure#Fermi estimation#ancient warfare
What's the True Cost of One Avocado? Water, Carbon, and Nutrition
Physics & Science · Everyday Life

What's the True Cost of One Avocado? Water, Carbon, and Nutrition

One avocado (100 g flesh) gets dissected through three lenses: water, carbon, and nutrition efficiency. The math checks the popular "200-320 liters of water" claim against the primary dataset, tests how much transport mode swings the carbon footprint, and ranks avocado's nutrient-per-liter efficiency against four other fruits.

#avocado#water footprint#carbon footprint#LCA#nutrition#sustainability
Gas, Diesel, Hybrid, or EV — Which Is Cheapest Over 5 Years? At 7, the Answer Flips
Money & Economy · Everyday Life

Gas, Diesel, Hybrid, or EV — Which Is Cheapest Over 5 Years? At 7, the Answer Flips

A car's sticker price is just the opening bid. Add in fuel, insurance, registration tax, maintenance, and resale value, and the total cost of ownership (TCO) tells a very different story. We run the numbers on a Hyundai Tucson in gasoline, diesel, and hybrid trims plus an IONIQ 5 EV — and the cheapest car changes not once but twice as ownership length and annual mileage shift.

#TCO#electric-vehicle#hybrid#diesel#gasoline#depreciation