Find the value of (?) in the following number series.
`6300," "?," "525," "105," "17.5" "2.5`

Options

A. A)2400
B. B)2100
C. C)4200
D. D)5200

Answer

To find the missing value in the number series: `6300, ?, 525, 105, 17.5, 2.5`, we will analyze the pattern of the series step by step.

### Step 1: Identify the pattern
We start from the last known value and work our way backward to find the missing term. The series is:
- 2.5
- 17.5
- 105
- 525
- ?

### Step 2: Calculate the multipliers
1. From 2.5 to 17.5:
- \( 17.5 = 2.5 \times 7 \)

2. From 17.5 to 105:
- \( 105 = 17.5 \times 6 \)

3. From 105 to 525:
- \( 525 = 105 \times 5 \)

### Step 3: Establish the pattern of multipliers
The multipliers are decreasing by 1 each time:
- 7 (for 2.5 to 17.5)
- 6 (for 17.5 to 105)
- 5 (for 105 to 525)

### Step 4: Find the missing term
Now, we need to find the term before 525. According to the pattern, the next multiplier should be 4:
- \( 525 = ? \times 4 \)

To find the missing term (let's denote it as K):
- Rearranging gives us:
- \( K = \frac{525}{4} \)
- \( K = 131.25 \)

### Step 5: Find the term before K
Now we need to find the term before K using the multiplier of 3:
- \( K = 6300 \times 3 \)
- \( K = 6300 / 3 \)
- \( K = 2100 \)

### Conclusion
The missing value in the series is \( 2100 \).

### Final Answer
The value of (?) is **2100**.

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