13
17,19,23,29
It is 7.
17... and 19 !
The numbers between 10 and 20 that are not prime are 12, 14, 15, 16 and 18. So 15 is the odd number and the rest are even numbers.
23
13
17,19,23,29
40/4=10 60/4=15 Then the second prime are between 10 and 15, two prime numbers: 11 and 13 The prime number is between 44 and 52 : 47
15
It is 7.
17... and 19 !
The numbers between 10 and 20 that are not prime are 12, 14, 15, 16 and 18. So 15 is the odd number and the rest are even numbers.
It is 19
7x11x13=1001
3*5 = 15 in prime numbers
15 is a factor of 45, but it is not a prime number.