PIN & HOLE PUZZLE (c) Ton Delsing

21 pieces. Material Acrylic. Front black, Back white. 
Some problems to solve. See below.

PUZZLE 1-   Use 21 pieces. Create a rectangle of 6x7 squares.

PUZZLE 2-  Use 21 pieces. Create a rectangle of 3x14 squares.

PUZZLE 3-  Use 20 pieces. Create a rectangle of 4x10 squares.

PUZZLE 4-  Use 18 pieces. Create a rectangle of 4x9 squares.

PUZZLE 5-  Use 20 pieces. Create 2 rectangles of 4x5 squares.

PUZZLE 6-  Use 18 pieces. Create a square of 6x6 squares.

PUZZLE 7-  Use 16 pieces. Create 2 squares of 4x4 squares.

NOTE: IN EACH HOLE SHOULD BE A PIN.