Question

Express the number as the sum of 2 consecutive primes.
. 18

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Answer 1

Answer:

b henry krna parker uytr

Answer 2

Step-by-step explanation:

Which of the following numbers can be expressed as the sum of 2 numbers consecutive primes?

I) 20 II) 36 III) 52

The correct answer is II) and III)

I solved it by explaining it as odd numbers:

36 = (2n + 1) + (2n + 3)

36 = 4n + 4 / n

8 = n

(2* 8 + 1) + (2 * 8 + 3) = 17 + 19 = 36

That worked fine, but with 52 no, since nothing assured me, that those two numbers were primes, they only assured me that they were odd.

So when doing the same with 52:

52 = 4n + 4 / n

12 = n

(2*12 + 1) + (2* 12 + 3) = 25 + 27 = 52

The sum is correct, but none is prime. The only thing I did to solve it, was to look for prime numbers around those two odd numbers. But for large numbers this will be quite tedious, then, how are these types of exercises solved regularly?

example only !