Jack, who is registered for GST, buys a car costing $44,000 (GST-inclusive) on 8 September 2020 from a GST-registered car dealer. Jack intends that 55 per cent of the car's mileage will be for his GST-registered race car driver tutoring enterprise, and 45 per cent for his own private use. At the end of April 2021, Jack calculates that the car was actually used 72 per cent of the time for business purposes and 28 per cent of the time for non-business purposes 

 What is the effect on the net amount of GST of the above events?