Can wash (2+3) × 20 = 100, * * * wash 134- 100 = 34.

If a washes dishes 1 minute, the number is 9-3 = 6.

B If you wash dishes 1 minute, the number is 7-2 = 5.

Because 6× 4+5× 2 = 34,

So the number of dishes is 4× 9+2× 7 = 50.

The number of dishes is 134-50 = 84.