What will come in place of the question mark (?) in the following numbers ?
25 16 ? 4 1

Options

A. 3
B. 6
C. 12
D. 9

Answer

To find the number that will replace the question mark (?) in the sequence 25, 16, ?, 4, 1, we can look for a pattern in the numbers.

1. **Identify the numbers**: The given sequence is 25, 16, ?, 4, 1.

2. **Recognize the squares**: Notice that these numbers can be expressed as squares of integers:
- 25 = 5²
- 16 = 4²
- ? = ?
- 4 = 2²
- 1 = 1²

3. **Determine the missing square**: The sequence of squares is decreasing:
- 5² (25)
- 4² (16)
- ? (which should be 3²)
- 2² (4)
- 1² (1)

4. **Calculate the missing value**: Since the missing number corresponds to 3²:
- 3² = 9

5. **Conclusion**: Therefore, the number that will come in place of the question mark is 9.

**Final answer**: 9

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