1,4,9,16,20,36,49

Options

A. 1
B. 9
C. 20
D. 49

Answer

To determine the odd term in the series 1, 4, 9, 16, 20, 36, 49, we can analyze the pattern of the numbers given.

### Step-by-Step Solution:

1. **Identify the Pattern**:
The numbers in the series appear to be perfect squares. Let's list them out:
- 1 = 1²
- 4 = 2²
- 9 = 3²
- 16 = 4²
- 20 (not a perfect square)
- 36 = 6²
- 49 = 7²

2. **List the Perfect Squares**:
From the analysis, we see that:
- 1, 4, 9, 16, 36, and 49 are perfect squares of integers (1, 2, 3, 4, 6, and 7 respectively).
- The missing perfect square in the sequence is 25, which would correspond to 5².

3. **Identify the Odd Term**:
Since 20 is not a perfect square, while all other numbers are, we can conclude that 20 is the odd term in this series.

4. **Final Conclusion**:
Therefore, the odd term out in the series is **20**.