The net price equivalent rate of 10/12/16/ is I came up with .00192 is this right

Assuming the 10/12/16 is supposed to be the discounts, no. Don't ever try to multiply discounts - it doesn't work. If you get 10% off, then you're paying 90%. If you take 12% of 10%, you're taking 12% of the amount you already got off, so there isn't any point to that. Just doesn't work.

You have to multiply the compliments, or whatever your book might call them. That is, the compliment of 10% is 90%, whatever adds back up to 100%. If you got 10% off something, you would pay 90% of it. Do the compliments of each one and then multiply those.

That will be the equivalent in percent that you will pay for everything.