Best Guess · Puzzle #32 · Saturday, October 31
Best Guess: the answers
Four questions, each with one true number. Here they are with their answers, how to reason each one out, and where the number comes from. Play today's Best Guess.
1. How many new cars and light trucks were sold in the US in 2025?
The answer: about 16.2 million. Sales rose 2.4% from 2024.
Napkin math - 280Mcars and trucks on US roads
- ÷15years a vehicle lasts
≈18.7Mvehicles
The real answer is about 16.2 million vehicles (National Automobile Dealers Association). On a napkin, take 280 million cars and trucks on US roads, divided by 15 years a vehicle lasts, and you get about 19 million vehicles. That comes out 1.2 times too high, and a guess that far off still scores 9.4 out of 10. The target is wider than it looks: every guess between 8.1 million vehicles and 32 million vehicles scores at least 7.0.
2. How many pounds of peanut butter did Americans eat in 2023?
The answer: about 1.45 billion. Peanut butter is the biggest way Americans eat peanuts, well ahead of snack peanuts.
Napkin math - 130Mhouseholds in the US
- ×121-pound jars each a year (one a month)
≈1.56Bpounds
The real answer is about 1.45 billion pounds (USDA Economic Research Service). On a napkin, take 130 million households in the US, times 12 1-pound jars each a year (one a month), and you get about 1.6 billion pounds. The estimate is 1.1 times too high, close enough to score 9.7 out of 10. Any guess from 730 million pounds to 2.9 billion pounds scores 7.0 or better, because the game only counts how many times off you are.
Source: USDA Economic Research Service, Food Availability (Per Capita) Data System: Peanuts and tree nuts
3. How many hairs does a typical person shed in a year?
The answer: about 27,000. Dermatologists say losing 50 to 100 hairs a day is normal, because new hairs keep growing in.
Napkin math - 100hairs a day in the brush and the drain
- ×365days a year
≈36.5khairs
The true figure is about 27,000 hairs (American Academy of Dermatology). Without looking anything up, take 100 hairs a day in the brush and the drain, times 365 days a year, and you get about 37,000 hairs. That comes out 1.3 times too high, and a guess that far off still scores 8.8 out of 10. Because only the ratio counts, anything between 14,000 hairs and 55,000 hairs was worth 7.0 or more.
Source: American Academy of Dermatology, Do you have hair shedding or hair loss?
4. For the August 2017 total solar eclipse, how many US adults traveled away from home to see it?
The answer: about 20 million. Most were chasing a higher degree of totality, inside the narrow path where the Sun goes fully dark.
Napkin math - 250Madults in the US
- ÷10adults per eclipse traveler (about 1 in 10)
≈25Madults
The true figure is about 20 million adults (University of Michigan). Without looking anything up, take 250 million adults in the US, divided by 10 adults per eclipse traveler (about 1 in 10), and you get about 25 million adults. The estimate is 1.3 times too high, close enough to score 9.0 out of 10. Any guess from 10 million adults to 40 million adults scores 7.0 or better, because the game only counts how many times off you are.
Source: University of Michigan (via Futurity), 215 million U.S. adults watched the solar eclipse