Given:
Total length of the board = 91 cm
Let the length of the shortest piece = x cm
Then,
Second piece = (x + 3) cm
Third piece = 2x cm
Condition 1: Total length constraint
x + (x + 3) + 2x ≤ 91
4x + 3 ≤ 91
4x ≤ 88
x ≤ 22
Condition 2: Third piece is at least 5 cm longer than the second
Third piece ≥ Second piece + 5
2x ≥ (x + 3) + 5
2x ≥ x + 8
x ≥ 8
Possible values of x:
From both conditions,
8 ≤ x ≤ 22
Graphical Representation on Number Line:
Closed circles at 8 and 22,
with the region between 8 and 22 shaded.
Final Answer:
The possible lengths of the shortest board are
between 8 cm and 22 cm (inclusive).