2 6 15 30 45 43.5 22.5

Options

A. 6
B. 30
C. 45
D. 43.5

Explanation

To find the wrong number in the series: 2, 6, 15, 30, 45, 43.5, 22.5, we will analyze the pattern in the series step by step.

### Step-by-Step Solution:

1. **Identify the Pattern**:
We will look for a pattern in how the numbers are generated. The series appears to be increasing, and we may suspect that multiplication is involved.

2. **Check the First Pair (2 and 6)**:
- Divide 6 by 2:
\[ 6 \div 2 = 3 \]
- This suggests that 2 is multiplied by 3 to get 6:
\[ 2 \times 3 = 6 \]

3. **Check the Second Pair (6 and 15)**:
- Divide 15 by 6:
\[ 15 \div 6 = 2.5 \]
- This suggests that 6 is multiplied by 2.5 to get 15:
\[ 6 \times 2.5 = 15 \]

4. **Check the Third Pair (15 and 30)**:
- Divide 30 by 15:
\[ 30 \div 15 = 2 \]
- This suggests that 15 is multiplied by 2 to get 30:
\[ 15 \times 2 = 30 \]

5. **Check the Fourth Pair (30 and 45)**:
- Divide 45 by 30:
\[ 45 \div 30 = 1.5 \]
- This suggests that 30 is multiplied by 1.5 to get 45:
\[ 30 \times 1.5 = 45 \]

6. **Check the Fifth Pair (45 and 43.5)**:
- Divide 43.5 by 45:
\[ 43.5 \div 45 = 0.9667 \text{ (approximately)} \]
- This does not follow the previous pattern of decreasing multipliers (from 3 to 2.5 to 2 to 1.5). Instead, we would expect a multiplier of 1 based on the pattern.

7. **Calculate What Should Follow 45**:
- If we follow the established pattern, after multiplying by 1.5, we should multiply by 1:
\[ 45 \times 1 = 45 \]
- Hence, the next number should be 45, not 43.5.

8. **Identify the Wrong Number**:
- Since the expected number after 45 should be 45, the wrong number in the series is 43.5.

### Conclusion:
The wrong number in the series is **43.5**.