Решение:
- \( 40 \times 800 : 160 = 32000 : 160 = 200 \)
- \( 6800 \times 20 : 80 = 136000 : 80 = 1700 \)
- \( 90 \times 6000 : 27000 = 540000 : 27000 = 20 \)
- \( 300 : 50 \times 300 = 6 \times 300 = 1800 \)
- \( 210 \times 400 : 1400 = 84000 : 1400 = 60 \)
- \( 7000 : 140 \times 30 = 50 \times 30 = 1500 \)
- \( 4200 : 70 \times 3 = 60 \times 3 = 180 \)
- \( 1200 : 80 \times 400 = 15 \times 400 = 6000 \)
- \( 1200 : 600 \times 300 = 2 \times 300 = 600 \)
- \( 500 \times 400 : 100 = 200000 : 100 = 2000 \)
- \( 720 \times 10 : 80 = 7200 : 80 = 90 \)
- \( 64000 : 160 \times 30 = 400 \times 30 = 12000 \)
- \( 54000 : 18000 \times 50 = 3 \times 50 = 150 \)
- \( 20 \times 50 : 1000 = 1000 : 1000 = 1 \)
Ответ: 200, 1700, 20, 1800, 60, 1500, 180, 6000, 600, 2000, 90, 12000, 150, 1.