Answer:
Parts of oil in 42 cups of marinade = 21 cups
Parts of soy sauce in 42 cups of marinade = 14 cups
Parts of orange juice in 42 cups of marinade = 7 cups
Step-by-step explanation:
Given that:
Parts of oil = 3
Parts of soy sauce = 2
Part of orange juice = 1
Total cups of marinade = 42
To find:
How much of each ingredient should be there ?
Solution:
This problem can be solved by taking the ratio of ingredients into account.
The ratio is:
Oil : Soy Sauce : Orange Juice = 3 : 2 : 1
So, we can let the parts of oil = 
Parts of soy sauce = 
Parts of orange juice = 
As per the question statement:

So, parts of oil in 42 cups of marinade = 3
7 = 21 cups
Parts of soy sauce in 42 cups of marinade = 2
7 = 14 cups
Parts of orange juice in 42 cups of marinade = 7 cups