Face Mask Penatly -- NFHS rule

[LeRoy]

I do not have my rule book in front of me, but here is my question.. 1st and 10. A on the 40 yard line. A1 hands off to A2 that runs into a crowd of B players, then turns around and runs backwards and is tackled at A's 20 yard line during the tackle B3 brings A down by the face mask. My question is that a spot foul enforced from the 20 yard line for 15 yards and replay 1st down or do we go back to the previous spot and pentilze 15 form there.