It is: 24+23-9 = 38
23
23
5
23 or 41
20 and 43
The sum of all prime numbers less than 30 is 129.
Prime numbers >20 and <30 are 23 and 29. Total value 52.
The prime number that is greater than 20 but less than 29 is 23.
46
11
A deficient number is one for which the sum of its factors, with the exception of itself, is less than the number itself. Or alternatively, any number for which the sum of its factors including itself is two times the number in question. As 23 is a prime number, its only factor other than itself is 1. Another example of a deficient number close to 23 is 26 - its factors, other than itself, are 1, 2, and 13, which, added together, equals 16. The opposite of a deficient number is an abundant number.
23 and all numbers less than 23 is your answer. I would say to write it down that the answer is { 23, 22 21........... }