Reasoning : General Mental Ability

Q 22 / 45

UPSC CSE Prelims 2018

Consider the following three-dimensional figure:

Figure for the question: Consider the following three-dimensional figure: How many triangles does the above figure…

How many triangles does the above figure have?

EXPLANATION

Correct Option (B)

The total number of triangles in the given three-dimensional figure can be determined by systematically enumerating the triangles present in its distinct sections.

  • The uppermost section of the figure contains 5 distinct triangles.
  • The lowermost section of the figure also contains 5 distinct triangles.
  • The central connecting layer or structure within the figure comprises 10 distinct triangles.

Summing these counts provides the total number of triangles:

5 (upper) + 5 (lower) + 10 (central) = 20 triangles.

Incorrect Options:

Options A (18), C (22), and D (24) are incorrect because a comprehensive enumeration of all triangles within the figure, as detailed above, yields a total of 20 triangles. These options do not reflect the accurate count derived from a systematic analysis of the figure's components.

Explanation figure for the question: Consider the following three-dimensional figure: How many triangles does the above figure…