How many milliliters of a 2000.0 mg/dl stock solution are needed to prepare 100.0 ml of a 150.0 mg/dl working solution?

Answer 1

I answered one of your dilution/solution questions for you. I expect to see some work before I help with the others.

Answer 2

2000/100=150/x =7.5 ml?

Answer 3

That looks ok to me.