what should come in place of question mark 8544 1420 280 ? 18 5

Options

A. 33
B. 44
C. 56
D. 66

Answer

To find the missing number in the series 8544, 1420, 280, ?, 18, 5, we can observe the pattern of division and subtraction that is being applied to the numbers.

### Step-by-Step Solution:

1. **Identify the Pattern**:
- The series appears to be decreasing. Let's look at the first few numbers:
- 8544 to 1420
- 1420 to 280

2. **Calculate the First Transition**:
- To go from 8544 to 1420, we can divide 8544 by 6 and check:
\[ 8544 \div 6 = 1424 \quad (\text{not exactly } 1420) \]
- Instead, we can see that:
\[ 8544 \div 6 - 4 = 1420 \]

3. **Calculate the Second Transition**:
- Next, we go from 1420 to 280:
\[ 1420 \div 5 - 4 = 280 \]

4. **Determine the Next Number**:
- Now, we will apply the same logic to find the missing number (let's call it x):
- We divide 280 by 4 and then subtract 4:
\[ 280 \div 4 = 70 \]
\[ 70 - 4 = 66 \]
- So, the missing number is 66.

5. **Verify the Next Transition**:
- Now, we check if the pattern holds for the next number (18):
- We divide 66 by 3 and subtract 4:
\[ 66 \div 3 = 22 \]
\[ 22 - 4 = 18 \]
- This confirms our pattern is correct.

### Conclusion:
The missing number in the series is **66**.