Hi, I'm new here and very poor at math in general. I'm wondering, is there a simple formula of sorts for finding out how many combinations of two different numbers there are that equal another number? For example, how many combinations of 3's and 5's are there that equal 16? Such as, 3-5-3-5, 3-3-5-5, 3-5-5-3, 5-5-3-3 and 5-3-3-5. Thanks

Mike