What is the least number of straight lines needed to draw the figure given below?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 10
Each full straight line counts once, however many pieces other lines cut it into. In the figure below every line is numbered; group them by direction.
Horizontal lines (3): 1, 2, 3
Vertical lines (4): 4, 5, 6, 7
Slanting lines (3): 8, 9, 10
Total \(=3+4+3=10\) straight lines.
Why the other options are incorrect
Option (1) 16 — Incorrect. This counts every piece between two corners or crossings as a separate line.
Option (2) 6 — Incorrect. This leaves out the 4 vertical lines.
Option (3) 7 — Incorrect. This leaves out the 3 slanting lines.