7 / 20 ÷ (8 / 9-5 / 12) × 9 / 10

7 / 20 ÷ (8 / 9-5 / 12) × 9 / 10

7 / 20 ÷ (8 / 9-5 / 12) × 9 / 10
=7 / 20 ÷ (32 / 36-15 / 36) × 9 / 10
=7 / 20 ÷ 17 / 36 × 9 / 10
=7 / 20 × 17 / 36 × 9 / 10
=63 / 85 × 9 / 10
=567 out of 850