31
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Hello,
By the Fundamental Theorem of Arithmetic, all composite numbers can be written as product of primes. There is also another theorem that states that one of those primes must be smaller then the square root of that number. If any of the prime numbers can divide evenly into the number, then it is composite (as its composed of that prime) else its prime.
So, √31=5.56. Prime numbers to 5 include 2,3, and 5. None of these divide into it, so 31 is prime.
By the Fundamental Theorem of Arithmetic, all composite numbers can be written as product of primes. There is also another theorem that states that one of those primes must be smaller then the square root of that number. If any of the prime numbers can divide evenly into the number, then it is composite (as its composed of that prime) else its prime.
So, √31=5.56. Prime numbers to 5 include 2,3, and 5. None of these divide into it, so 31 is prime.
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aren't you glad you memorized all those multiplication tables?
31 isn't the answer to any of them. it's prime.
31 isn't the answer to any of them. it's prime.
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Prime... Because there are no numbers you can multiply and get 31.