2016 · Q60
Consider the following figure: a symmetric horizontal band of small equilateral triangles joined edge-to-edge in a zigzag pattern (wider at the ends, pinched in the middle). Which one of the following is the number of triangles in the figure given above?
general-mental-abilitynon-verbal-reasoning
- A22
- B27
- C28
- D29
Explanation
The figure is a symmetric horizontal band of small equilateral triangles joined edge-to-edge in a zigzag, wider at the ends and pinched in the middle. Counting systematically, smallest unit triangles first and then the larger composite triangles formed along the top ridge, the diagonals, and the pinched centre, the total number of triangles is 27. Options 22, 28, and 29 miscount the composite triangles.