Li Jun (registered for GST) has rented three investment properties and receives $9,000 monthly rent ($3,000 from a residential property and $3,000 each from two commercial properties). In February 2020, Li Jun hires services of Tony, a GST-registered repairer, to undertake repair work that relates equally to all rented properties. Tony invoices Li $4,950 (incl GST) for the repair service. Advise both Li Jun and Tony on how the GST law applies to each of them. Your answer must be supported by relevant legislation. Show relevant GST calculations for their quarterly Business Activity Statement.