1. A sheet of cardboard measuring 48 cm in length and 36 cm in width needs to be cut into cards measuring 16 cm in length and 12 cm in width. How can this be done to obtain the maximum number of cards?
1. In the first step, it is necessary to determine how many cards will fit if the length of each is $16 (48: 16=3)$. Then determine how many cards will fit in the width (36:12 = 3).

Finally, find the number of cards $(3 \times 3=9)$. Then conduct similar reasoning for the case where the cards are laid out by width ( $48: 12=4,36: 16=2$ (remainder 4), $4 \times 2=8$ ). Now we can conclude that the maximum number of cards is 9.

Answer: cut the length into three equal parts of 16 cm, and then cut each of the resulting parts into 3 more parts - 12 cm each.