Almonds: 20
Walnuts:
Pecans:40
Since the ratios are 4,3, and 8, the best way to do it is to use a proportion.

So yeah what you do it cross multiply and get 120=8x
divide by 8 and get 15.
15 ounces of walnuts.
Now for total just find the last part.
Since 4 is half of 8, the number of ounces is half of 40, which is 20.
So 20+40+15? You guessed it 75 ounces of Granola.
Hope that made sense.