BPSC – Combined Competitive Examination · Question 8
What should come in place of the question mark (?) in the following figures? Figure 1: upper pair 16, 21; lower pair 15, 10; centre 36 Figure 2: upper pair 7, 10; lower pair 13, 10; centre 16 Figure 3: upper pair ?, 15; lower pair 21, 14; centre 64
Show answer & explanation
Answer: (A) 22
Explanation
In each figure the cross sums match (16+15 = 21+10) and the centre is (pair difference + 1)². For figure 3, ? + 14 = 15 + 21 = 36, so ? = 22.
- (A) Correct
Correct: centre = (difference + 1)²; 64 = 8² gives difference 7, so ? = 15 + 7 = 22 (also ? + 14 = 15 + 21).
- (B) Incorrect
Wrong: 18 + 14 = 32 ≠ 36.
- (C) Incorrect
Wrong: does not fit the pattern.
- (D) Incorrect
Wrong: 20 + 14 = 34 ≠ 36.