Since it is odd, 4, 6 and 10 cannot be divisors.
5 cannot be a divisor since when you count by 5's you get numbers ending in 5 or 0
(5,10,15,20, etc)
9 cannot be a divisor since 9 x 6 = 54 and 9 sx 7 = 63
None of your answers will work with 57.
3 will work even though you did not list it. 5+7 = 12 and 1+2 = 3. If the sum of the digits = 3, 6 or 9, the number is divisible by 3.
45 is divisible by 3 (4+5=9)
78 is divisible by 3 (7+8=15 and 1+5 = 6)
