Answer:
1. 9
2. 13.75 i guess
3. 328
1) 20 ÷ 4 × 5 - 16
= 5 × 5 - 16
= 25 - 16
= 9
2) 3 × [5 + (40 ÷ 8) × 2)
= 3 × (5 + 5 × 2)
= 3 × (5 + 10)
= 3 × 15
= 45
3) 33 - 2 × (24 ÷ 3) + 10
= 33 - 2 × 8 + 10
= 33 - 16 + 10
= 17 + 10
= 27
