0.0256
39
2
It is 39*n+1 when divided by n, for any integer n.
The average of 148 and 39 is the sum of 148 and 39 divided by 2, or 187/2, or 93.5
7 divided by 13 times 2 divided by 3 is 14/39
3 and 13
78 / 2 is 39
4.0769
1339 divided by 13 is 3 26 divided by 13 is 2
2
To work it out for yourself, you need to understand that a prime number is a number than can only be divided by 1 and itself. 18 can be divided by 2 39 can be divided by 3 42 can be divided by 2 which leaves 31 which can only be divided by 1 and 31.