There are (40-x) cranes.

4x+2(40-x)= 1 12

4x+80-2x= 1 12

2x=32

x= 16

There are 16 turtles.

24 cranes

2: 960 ÷ (120 ÷ 4) = 12 minutes

3: This shipment is ***x tons.

( 1-2/5)x=6+9

3/5x= 15

x=25

This shipment is ***25 tons.

4:3. 14*0.5? * 1=0.785cm？

0.785*36=28.26cm？

28.26/(3. 14*0.6? ) =25 days