Best Guess · Puzzle #38 · Friday, November 6
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 pieces of mail did the US Postal Service process and deliver on an average day in fiscal 2025?
The answer: 361.1 million. That is over 4,000 mailpieces every second, around the clock.
Napkin math - 130Mhouseholds in the US
- ×3pieces of mail each a day
≈390Mmailpieces
The answer comes to 361.1 million mailpieces (United States Postal Service). On a napkin, take 130 million households in the US, times 3 pieces of mail each a day, and you get about 390 million mailpieces. It's 1.1 times too high, which as a guess would still have scored 9.7 out of 10. The target is wider than it looks: every guess between 180 million mailpieces and 720 million mailpieces scores at least 7.0.
Source: United States Postal Service, Postal Facts - One Day
2. How many greeting cards do Americans buy each year?
The answer: about 6.5 billion. Birthday is by far the most popular everyday card occasion, and women buy an estimated 80% of all cards.
Napkin math - 330Mpeople in the US
- ×15cards each a year
≈4.95Bcards
The real answer is about 6.5 billion cards (Greeting Card Association, as of 2019). Without looking anything up, take 330 million people in the US, times 15 cards each a year, and you get about 5 billion cards. That comes out 1.3 times too low, and a guess that far off still scores 8.8 out of 10. The target is wider than it looks: every guess between 3.3 billion cards and 13 billion cards scores at least 7.0.
3. How many Peeps marshmallow candies does Just Born make in a year?
The answer: about 2 billion. The factory turns out about 5.5 million Peeps a day, and a chick that took 27 hours to make in 1953 now takes 6 minutes.
Napkin math - 330Mpeople in the US
- ×5Peeps each a year (one pack)
≈1.65BPeeps
The true figure is about 2 billion Peeps (Just Born). Without looking anything up, take 330 million people in the US, times 5 Peeps each a year (one pack), and you get about 1.6 billion Peeps. That comes out 1.2 times too low, and a guess that far off still scores 9.2 out of 10. Any guess from 1 billion Peeps to 4 billion Peeps scores 7.0 or better, because the game only counts how many times off you are.
Source: Just Born, Fun Facts
4. How many people in the US donate blood each year?
The answer: about 6.8 million. The Red Cross says only about 3% of age-eligible people give blood in a year.
Napkin math - 330Mpeople in the US
- ÷50people for every donor
≈6.6Mdonors
The true figure is about 6.8 million donors (American Red Cross). Without looking anything up, take 330 million people in the US, divided by 50 people for every donor, and you get about 6.6 million donors. That is almost exactly the real number, and a guess like it scores 9.9 out of 10. Because only the ratio counts, anything between 3.4 million donors and 14 million donors was worth 7.0 or more.