This is sort of a guess, but it makes sense in my head. I'm going to say 2/10, because for a number to be divisible by 5 it has to either end in a 5 or a 0, and those are 2 options out of 10. You could simplify 2/10 down to 1/5, which would be the final answer. I'm not sure, but this is the best I can offer. I hope this helps!
