The unsimplified ratio of raisins to mixed nuts in the trail mix is:
4/15 to 1/3
To simplify this, it is easiest to make 1/3 into an equivalent fraction with the denominator 15 by multiplying both the numerator and the denominator by 5.
1 * 5 / 3 * 5 = 5 / 15
If we substitute in this new value, our ratio is:
4/15 : 5/15
Because both of these fractions have the same denominators, we can just compare their numerators, so we can simplify our ratio to be:
4:5
Therefore, your final answer is a 4:5 ratio of raisins to mixed nuts.
Hope this helps!