Question

Study the given pattern carefully and select the number that can replace the question mark (?) in it:

[4    10    9]
[5    13    13]
[7    19    ?]

• A. 23
• B. 13
• C. 17
• D. 21

Hint:

When row patterns are unclear, try analyzing column-wise or diagonally. Pay attention to arithmetic progressions or difference sequences.

Answer 1

The Correct Option is D

Let's examine each row for a pattern.

Row 1: 4, 10, 9
⇒ 4 + 5 = 9, but that doesn’t explain 10. Try column-wise instead.

Column-wise analysis:
Column 1: 4, 5, 7
Column 2: 10, 13, 19
Column 3: 9, 13, ?

Column 2 shows:
From 10 to 13: +3
From 13 to 19: +6
→ So the pattern is increasing by +3, +6 — suggesting a progression.

Now, look at differences in Column 3:
From 9 to 13: +4
If the next difference is +8:
13 + 8 = 21

So, the missing number is 21.

Answer: 21