Not true.

Q: What is the difference between scientists and Engineers?

A: It can be demonstrated by the engineering approach to experimental data.
The engineer wants to show that all odd numbers are prime.
1 prime
3 prime
5 prime
7 prime
9 experimental error
11 prime
13 prime
15 experimental error
17 prime
19 prime
80% of the data show that odd numbers are prime numbers with only 20% experimental errors.
It is therefore reasonable to regard all odd numbers as primes.

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"Man has always found it easier to sacrifice his life than learn the multiplication table." - Somerset Maugham