Reasoning : Logical Reasoning & Analytical Ability

Q 283 / 325

UPSC CSE Prelims 2013

Examine the following three figures in which the numbers follow a specific pattern:

Figure for the question: Examine the following three figures in which the numbers follow a specific pattern: The m…

The missing number (?) in the third figure above is

EXPLANATION

Correct Option (B)

The figures follow a specific numerical pattern. Let the top number be 'A', the left number be 'B', and the right number be 'C'.

Upon examining the first two figures, a consistent relationship between 'B' and 'C' is observed:

  • In Figure 1: A=4, B=28, C=56. Here, C is twice B (56 = 2 × 28).
  • In Figure 2: A=5, B=45, C=90. Here, C is twice B (90 = 2 × 45).

This establishes the pattern that the rightmost number (C) is consistently double the leftmost number (B).

Applying this pattern to Figure 3:

  • A=8, B=?, C=32.
  • According to the established pattern, C = 2 × B.
  • Substituting the known value for C: 32 = 2 × B.
  • Solving for B: B = 32 / 2 = 16.

Therefore, the missing number in the third figure is 16.

Incorrect Options:

  • Options A (7), C (21), and D (28) are inconsistent with the derived pattern (C = 2 × B). If the missing number (B) were 7, 21, or 28, the relationship with C=32 would not hold true (i.e., 32 ≠ 2 × 7, 32 ≠ 2 × 21, and 32 ≠ 2 × 28).
Explanation figure for the question: Examine the following three figures in which the numbers follow a specific pattern: The m…