Answer: 16
Step-by-step explanation: when ur doing subtacting ur gonna notice a pattern like 11.25 10.75 10.25 9.75 9.25 because if u start with 19 and minus 0.50 the u get ur answers 16 the 11.25 dosnt count because that for the gift after u spend 7.24 on the gift ur gonna have 11.25 and keep couniting down but also keep tract on how many it takes to get to 2.75