Find the wrong number in series
`6,3,3,4,9,22.5, ?`

Options

A. 4
B. 3
C. 9
D. 22.5

Answer

To find the wrong number in the series `6, 3, 3, 4, 9, 22.5, ?`, we can analyze the pattern of the series step by step.

### Step 1: Identify the pattern
Let's look at the first two numbers:
- The first term is 6.
- The second term is 3.

To get from 6 to 3, we can see that:
\[ 6 \times 0.5 = 3 \]

### Step 2: Continue the pattern
Now, let's look at the next term:
- The second term is 3.
- The third term is also 3.

To get from 3 to 3, we can see that:
\[ 3 \times 1 = 3 \]

### Step 3: Next term calculation
Now, let's look at the next term:
- The third term is 3.
- The fourth term is 4.

To get from 3 to 4, we can see that:
\[ 3 \times \frac{4}{3} = 4 \]

### Step 4: Continue with the pattern
Now, let's look at the next term:
- The fourth term is 4.
- The fifth term is 9.

To get from 4 to 9, we can see that:
\[ 4 \times 2.25 = 9 \]

### Step 5: Next term calculation
Now, let's look at the next term:
- The fifth term is 9.
- The sixth term is 22.5.

To get from 9 to 22.5, we can see that:
\[ 9 \times 2.5 = 22.5 \]

### Step 6: Identify the incorrect term
Now, let's summarize the multipliers:
- From 6 to 3: multiplied by 0.5
- From 3 to 3: multiplied by 1
- From 3 to 4: multiplied by \(\frac{4}{3}\)
- From 4 to 9: multiplied by 2.25
- From 9 to 22.5: multiplied by 2.5

We notice that the multiplier from 3 to 4 does not fit the pattern. Instead of 4, if we had 4.5, the series would have continued smoothly:
- From 3 to 4.5: multiplied by 1.5
- From 4.5 to 9: multiplied by 2

Thus, the wrong number in the series is **4**.

### Final Answer
The wrong number in the series is **4**.