The fraction of the trail mix that will be raisins is 1/3 and the fraction that will be M&M's candy is 1/5. To find the fraction of the mix that will be nuts, we need to subtract the sum of these two fractions from 1 (since 1 represents the whole mix).
So, the fraction of the mix that will be nuts is 1 - 1/3 - 1/5.
To find a common denominator, we multiply 3 and 5 to get 15.
1 - 1/3 - 1/5 = 15/15 - 5/15 - 3/15 = (15 - 5 - 3)/15 = 7/15.
Therefore, 7/15 of the mix will be nuts.