Question 34936
The combination of four things (Milk, Yogurt, Cottage Cheese, Cheddar Cheese) taken three at a time is expressed by:{{{nCr = n!/(r!(n-r)!)}}} where: n = 4 and r = 3
{{{4C3 = 4!/(3!(4-3)!)}}}
{{{4C3 = 4!/3!(1)!}}}
{{{4C3 = 4}}}

You can have four different combinations of three dairy products:

1) Milk, Yogurt, Cottage cheese.
2) Milk, Yogurt, Cheddar cheese.
3) Milk, Cottage cheese, Cheddar cheese.
4) Yogurt, Cottage cheese, Cheddar cheese.