Arrange the positive odd numbers as follows (3,5,7); (9,11,13,15,17), and ask which group of numbers is 2005

Arrange the positive odd numbers as follows (3,5,7); (9,11,13,15,17), and ask which group of numbers is 2005

Let an = 2n + 1, so n = 1002 (1002nd)
Then, because the number ratio of each is 3, 5, 7
So let BN = 2n + 1, s (BN) = (n + 2) * n
Because s (B30) = 960, s (B31) = 1023, so in group 31

To answer the following question, the edge lengths of the three cubes are 2 cm, 3 cm and 6 cm respectively. The new three-dimensional figure is obtained by gluing them together
1. The edge lengths of the three cubes are 2 cm, 3 cm and 6 cm respectively. What is the minimum surface area of the new three-dimensional figure obtained by gluing them together?
Big brothers and sisters, please help me

In the least sticking method, two small squares are placed on the big square, and the surface area of the new three-dimensional figure is to subtract the area of two 2 cm squares, and then subtract the sum of two 2 and 3 squares,
S = 6x2x2 + 6x3x3 + 6x6x6-4x2x2-2x3x3 = 260 square centimeters