Answer:

Tortoise: (112-40× 2) ÷ (4-2) =16 (only)

Crane: 40- 16 = 24 (only)

2. Small boat: (6× 8-38) ÷ (6-4) = 5 (pieces)

Big ship: 8-5 = 3 (pieces)

3. Assuming all boys, planting 3× 12=36 trees is more than planting 36-32 = 4 trees, because it is assumed that girls are boys.

Female: (3× 12-32) ÷ (3-2) = 4 (person)

Male: 12-4 = 8 (person)