221
It is their lowest common multiple which is 221 13 and 17 are both prime numbers
Nothing goes into 13 evenly other than 1 and 13, so that means it is a prime number.
n + 20 - 17 + 13 - n = 20 - 17 + 13 = 3 + 13 = 16
17
221
Themselves and their multiples because 17 and 13 are both prime numbers.
It is their lowest common multiple which is 221 13 and 17 are both prime numbers
The whole number between 13 and 17 is 15
Nothing goes into 13 evenly other than 1 and 13, so that means it is a prime number.
n + 20 - 17 + 13 - n = 20 - 17 + 13 = 3 + 13 = 16
17
It is 30 because 30-17 = 13
1 and 17 (17 is a prime number).
17 is prime and 68 is 17 times 4, so the number that can go into 17 and 68 is 17.
17.
13