Dr Jones runs a medical practice andbotoxclinic (note: Abotoxtreatment is treated as a cosmetic procedure which temporarily paralyses targeting muscles in the face to give a more youthful appearance). During the 2017/18 income year, he derived the following supply amounts (inclusive of GST where applicable):

GROSS fees from patients for medical services$375,000

GROSS fees frombotoxtreatments (purely cosmetic)$275,000

GROSS wages for lecturing at university$45,000

Interest received on business bank account$15,000

GROSS payments received from selling plain bottled water$3,300

GROSS payments received from selling sparkling bottled water$3,300

He also incurs the following expenses (inclusive of GST where applicable)

Botox injections$27,500

Bottled water (plain) to sell in his practice$550

Bottled water (sparkling) to sell in his practice$550

Computer for private use$1,650

Wages (1 x employee)$25,000

(a)Calculate the GST payable on supplies for the 2018/19 income year

(b)Calculate the GST tax credits on for the 2018/19 income year

(c)What is Dr Jones' net GST position for the 2018/19 income year?