Conundrum: Non-Prime

I’m thinking of a two-digit number that is not a prime, the sum of two primes, or the product of two primes.

What number am I thinking of?

UPDATE: Question answered by Bronx Richie. See comments for answer.

4 Responses to “Conundrum: Non-Prime”

  1. 100%Tuna (kunaalw@gmail.com) Says:

    now THAT’s an easy one…
    you’re thinking of 21…
    i.e. not prime as it has non-1 and non-21 factors i.e. 7 ^ 3
    product of two primes: 7, 3
    sum of 2 primes: 19, 2

    BUT you could also be thinking of 14
    i.e. not prime as it has non-1 and non-14 factors i.e. 7 ^ 2
    product of two primes: 7, 2
    sum of 2 primes: 11, 3

    Or maybe 91?
    i.e. not prime as it has non-1 and non-91 factors i.e. 13 ^ 7
    product of two primes: 13, 7
    sum of 2 primes: 89, 2
    .
    .
    .
    BASICALLY YOUR QUESTION LACKS A UNIQUE SOLUTION. OR DID I INTERPRET THY QUESTION WRONGLY? (:
    Nice blog, btw!

  2. Bill Says:

    Welcome, Tuna!

    I meant that number is not prime, it is not the sum of two primes, and it is not the product of two primes.

    There is only one two-digit number that meets these three conditions.

  3. Bronx Richie Says:

    27 seems to meet all your requirements.

  4. Bill Says:

    Indeed it does. Nice work, Bronx Richie!

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