Direction: In the following number series questions one number is wrong. Find out the wrong number.
18.3 20.6 16 22.9 13.7 2.2 11.4

Options

A. 2.2
B. 16
C. 22.9
D. 20.6

Answer

To find the wrong number in the series: 18.3, 20.6, 16, 22.9, 13.7, 2.2, 11.4, we can analyze the pattern of the series step by step.

### Step 1: Identify the pattern
Let's look at the series:
- 18.3
- 20.6
- 16
- 22.9
- 13.7
- 2.2
- 11.4

We can see that the series alternates between increasing and decreasing numbers.

### Step 2: Calculate the differences
1. From 18.3 to 20.6:
- 20.6 - 18.3 = 2.3 (increase)
2. From 20.6 to 16:
- 16 - 20.6 = -4.6 (decrease)
3. From 16 to 22.9:
- 22.9 - 16 = 6.9 (increase)
4. From 22.9 to 13.7:
- 13.7 - 22.9 = -9.2 (decrease)
5. From 13.7 to 2.2:
- 2.2 - 13.7 = -11.5 (decrease)
6. From 2.2 to 11.4:
- 11.4 - 2.2 = 9.2 (increase)

### Step 3: Analyze the pattern of differences
- The increases are: 2.3, 6.9, and the next increase should follow a pattern.
- The decreases are: -4.6, -9.2, and the next decrease should also follow a pattern.

### Step 4: Check the expected values
1. The first increase is 2.3.
2. The second increase is 6.9, which is 2.3 + 4.6.
3. The next expected increase should be 6.9 + 4.6 = 11.5.

### Step 5: Check the decrease
1. The first decrease is -4.6.
2. The second decrease is -9.2, which is -4.6 - 4.6.
3. The next expected decrease should be -9.2 - 4.6 = -13.8.

### Step 6: Identify the wrong number
If we follow the pattern:
- After 13.7, we should have:
- Expected decrease: 13.7 - 11.5 = 2.2 (which is given)
- Expected next number after 2.2 should be 2.2 + 11.5 = 13.7 (which is not correct).

Thus, the number 2.2 is inconsistent with the expected pattern of the series.

### Conclusion
The wrong number in the series is **2.2**.