- **G1 (Total sales, GST-inclusive):** $110,000
- **1A (GST on sales):** $110,000 ÷ 11 = **$10,000**
- **1B (GST on purchases):** $66,000 ÷ 11 = **$6,000**
- **W2 (PAYG withheld):** 20% × $40,000 = **$8,000**
- **Net amount payable to the ATO:** (1A − 1B) + W2 = ($10,000 − $6,000) + $8,000 = **$12,000**