daily.surf

Best Guess · Puzzle #7 · Tuesday, October 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. 1. How many twin births were there in the US in 2024?

    The answer: about 109,000. Twins make up about 3 in every 100 US births.

    Napkin math
    1. 330Mpeople in the US
    2. ÷80years a lifetime
    3. ÷40babies for each twin

    ≈103ktwin births

    Source: CDC National Center for Health Statistics, FastStats - Multiple Births (Births: Final Data for 2024)

  2. 2. How many slices of pizza do Americans eat on an average day?

    The answer: about 128 million. Over half of that pizza comes from restaurants and about a quarter from grocery stores.

    Napkin math
    1. 330Mpeople in the US
    2. ÷10people per pizza eater (one in 10 has pizza on a given day)
    3. ×3slices each

    ≈99Mslices

    Source: USDA Agricultural Research Service, Food Surveys Research Group, Pizza Consumption in the U.S., What We Eat in America, NHANES 2017-March 2020 Prepandemic (Dietary Data Brief No. 62)

  3. 3. How many people in the US wear contact lenses?

    The answer: about 45 million. CDC runs a Contact Lens Health Week each August to cut the risk of eye infections among those wearers.

    Napkin math
    1. 330Mpeople in the US
    2. ÷7people per contact-lens wearer (about 1 in 7)

    ≈47.1Mpeople

    Source: CDC (MMWR), Contact Lens Health Week — August 19–23, 2019

  4. 4. How many toothbrushes do Americans throw away in a year?

    The answer: about 1 billion. Most of them are plastic, which is why National Geographic called the toothbrush part of the plastic crisis.

    Napkin math
    1. 330Mpeople in the US
    2. ×4toothbrushes each a year (a new one every 3 months)

    ≈1.32Btoothbrushes

    Source: National Geographic, How your toothbrush became a part of the plastic crisis

All of puzzle #7 · The archive