Answer:
36
Step-by-step explanation:
Pretty simple
Multiply the numbers of different type of wood by the different type of length by the different type of width which is 4x3x3 = 36
4 wood type A B C D
3 length type L1 L2 L3
3 width type 1 2 3
So for wood A we have, (L1, 1) (L1,2)(L1,3)(L2,1)(L2,2)(L2,3)(L3,1)(L3,2)(L3,3)
for wood B we have, (L1, 1) (L1,2)(L1,3)(L2,1)(L2,2)(L2,3)(L3,1)(L3,2)(L3,3)
for wood C we have, (L1, 1) (L1,2)(L1,3)(L2,1)(L2,2)(L2,3)(L3,1)(L3,2)(L3,3)
for wood D we have, (L1, 1) (L1,2)(L1,3)(L2,1)(L2,2)(L2,3)(L3,1)(L3,2)(L3,3) if we count the combinations together we will arrive at 36