the sum of the first 15 prime numbers is 328 .
15
The given numbers of 15 and 35 are not prime numbers but they add up to 50
They are: 2+13 = 15
There is only one square number from 5-15: 9. This can be written as the sum of 2 and 7, which are prime numbers.
It is 377.
If you mean the numbers are all 15 then the answer is 45 otherwise the answer is the 15 that you already stated in your question to be the sum.
15 is the product of two prime numbers; 3 x 5
The smallest is 15.
4, 5 and 6
Yes: 1 + 3 + 19 5 + 7 + 11 1 + 7 + 15
No. 15 is the product of two prime numbers: 3 and 5