Solution: Suppose there are X pieces of paper of type A and Y pieces of paper of type B,

According to the meaning of the question, there are 3x+6y≥45 (1).

5x+6y≥55 (2)

x，y∈N，

Find the minimum value of 2x+3y,

Let z=2x+3y, then y=-2/3x+ 1/3z.

Draw two lines (1) and (2) in a rectangular coordinate system. For the sake of convenience, here are only instructions, please draw them yourself.

This problem finds the minimum value of z, so we live around it according to the intersection of two lines.

Combination (1) and (2), x=5, y=5,

The substitution verification was established, and 5 sheets of each kind can minimize the material area.