okay heres how you can work it out,
Suppose you have a vial that contain 5,000 iu Human Chorionic Gonadotropin (HCG) powder.
If you mix it with 1 ml water, you have 5000 iu/ml.
If you mix it with 10 ml water, you have 500 iu/ml
If you mix it with 50 ml water, you have 100 iu/ml