Question about Prime

I'm Korean so I don't write English well...

So I wanna ask you A question about prime

The question is this.

p, q is prime (both) and they are satisfied "q = 2p + 1" than, proof this thesis

"multiple about P always have the number that The total number of digits is 3 or less."

Sorry about my English skill

example

p = 11, q = 23

q x 87 = 23 x 87 = 2001

2 + 0 + 0 + 1 = 3

#NumberTheory

Easy Math Editor

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Comments

$3$ is possible for $q$

Mohammad Farhat - 2 years, 7 months ago

thank you for the answer

but the question is 'proof' the thesis...

and 3 cannot possible of q (1 is not prime)

찬우 김 - 2 years, 7 months ago

I mean that $3 = 2(3) + 1 = 7$ and $3 & 7$ are prime.

Mohammad Farhat - 2 years, 7 months ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$