Direction: What should come in place of question mark in the following number series?
32 24 20 18 17 ?

Options

A. 16.5
B. 8.5
C. 12.5
D. 18.5

Answer

To solve the number series: 32, 24, 20, 18, 17, ?, we need to identify the pattern in the series.

### Step-by-Step Solution:

1. **Identify the first difference:**
- From 32 to 24:
\[ 32 - 24 = 8 \]
- From 24 to 20:
\[ 24 - 20 = 4 \]
- From 20 to 18:
\[ 20 - 18 = 2 \]
- From 18 to 17:
\[ 18 - 17 = 1 \]

2. **Observe the pattern in the differences:**
- The differences are: 8, 4, 2, 1.
- We can see that each difference is halved from the previous one:
- 8 (halved to get 4)
- 4 (halved to get 2)
- 2 (halved to get 1)

3. **Continue the pattern:**
- The next difference should be half of 1, which is:
\[ \frac{1}{2} = 0.5 \]

4. **Subtract this difference from the last number in the series:**
- From 17, we subtract 0.5:
\[ 17 - 0.5 = 16.5 \]

5. **Conclusion:**
- The number that should come in place of the question mark is:
\[ 16.5 \]

### Final Answer:
The answer is **16.5**.

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