11.8, 11.9, 12, 12.3, 13.8, 24.4, 118.8

Options

A. 11.9
B. 11.8
C. 12
D. 24.4

Explanation

To find the odd one out in the series: 11.8, 11.9, 12, 12.3, 13.8, 24.4, 118.8, we will analyze the differences between consecutive numbers and identify any irregularities.

### Step-by-Step Solution:

1. **Identify the series**: The given series is 11.8, 11.9, 12, 12.3, 13.8, 24.4, 118.8.

2. **Calculate the differences between consecutive terms**:
- Difference between 11.9 and 11.8:
\( 11.9 - 11.8 = 0.1 \)
- Difference between 12 and 11.9:
\( 12 - 11.9 = 0.1 \)
- Difference between 12.3 and 12:
\( 12.3 - 12 = 0.3 \)
- Difference between 13.8 and 12.3:
\( 13.8 - 12.3 = 1.5 \)
- Difference between 24.4 and 13.8:
\( 24.4 - 13.8 = 10.6 \)
- Difference between 118.8 and 24.4:
\( 118.8 - 24.4 = 94.4 \)

3. **List the differences**:
- The differences are: 0.1, 0.1, 0.3, 1.5, 10.6, 94.4.

4. **Identify the pattern in differences**:
- The first two differences are 0.1 (consistent).
- The third difference (0.3) is three times the first difference (0.1).
- The fourth difference (1.5) is five times the third difference (0.3).
- The fifth difference (10.6) appears to break the pattern, as it is not consistent with the previous differences.

5. **Check if 24.4 is the odd one out**:
- If we follow the pattern, the difference after 13.8 should be 10.5 (which is 7 times 1.5).
- Therefore, the next number should be:
\( 13.8 + 10.5 = 24.3 \).
- The number in the series is 24.4, which is incorrect.

6. **Conclusion**:
- The odd one out in the series is **24.4**. The correct number should be **24.3**.