A planar rectangular paper has two V-shaped pieces attached as shown below. This piece of paper is folded to make the following closed three-dimensional object (a prism-like shape with V-shaped cross-sections). The number of folds required to form the above object is
A. 9
B. 7
C. 11
D. 8
GATE 2024 · General Aptitude · Paper Folding · medium
Answer: The number of folds required is 9. Answer: A.
Count folds in the rectangular body: The central rectangle is divided into 4 face-panels by 3 vertical crease lines. Folding along these 3 lines bends the strip into a closed tube (the body of the prism). Body folds = 3.
Count folds in the left V-shaped tab: The V-piece on the left consists of 2 angled arms and a connecting base. It requires 3 fold lines: one at the attachment edge (connecting it to the rectangle), and one along each arm of the V. Left tab folds = 3.
Count folds in the right V-shaped tab: The right V-piece is symmetric to the left and also requires 3 fold lines. Right tab folds = 3.
Total folds: Adding the fold counts: 3 + 3 + 3 = 9 folds.