1: 2 1000 small cubes are piled into a big cuboid. The height of a large cuboid is 10 cm, and the length and width are greater than the height. What is the circumference of the bottom of a big cuboid?

2: rectangular iron sheet, 32 cm long. Subtract a square with a side length of 4 cm from its four top corners, then fold it and weld it into a rectangular tin box without a cover. It is known that the volume of this iron box is 768 cubic centimeters. What is the area of this rectangular piece of iron?

3. Rangers planted 74 trees every 4 meters on both sides of a highway. Now it's time to plant a tree every 6 meters. So, how many trees don't need transplanting?