Two possible answers are 7/10 and 13/20.
Explanation:
We can use common denominators to convert these fractions and find ones between them. Any multiple of 5 can be used, so the first one I chose was 10. You multiply 5 by 2 to make 10, so multiplying the numerator by 2, we get 6/10.
Doing the same thing to the other fraction, we multiply 4 by 2 and get 8/10. A fraction between 6/10 and 8/10 would be 7/10.
Now I will use 20. You multiply 5 by 4 to get 20, so 4*3 in the numerator would give you 12/20.
For the second fraction, 4*4 on the numerator would give us 16/20. One fraction between these two would be 13/20.