1 and 17.
340 = 20 x 17 357 - 340 = 17 17 times with 17 remaining
1, 3, 7, 17, 21, 51, 119, 357.
21 times.
Only the number 1.
Themselves and their multiples because 17 and 13 are both prime numbers.
The lowest possible number? Or just a number? A easy method would be to just multiply 17 & 19 17 X 19 = 323
It is their lowest common multiple which is 221 13 and 17 are both prime numbers
Quite a few. However the most obvious is 17*22 = 374.
136, 272, 408, 544, 680 +136 . . .
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 will go into both of them with no remainder