What will come in place of question mark(?) in given number series.
8 ? 40 60 60 30

Options

A. 15
B. 20
C. 18
D. 16

Answer

To solve the question of what will come in place of the question mark (?) in the given number series: 8, ?, 40, 60, 60, 30, we can follow these steps:

### Step 1: Identify the pattern in the series
We need to analyze the numbers in the series to find a relationship between them. The series is: 8, ?, 40, 60, 60, 30.

### Step 2: Look for a multiplication pattern
We can observe that the numbers seem to be related by multiplication. Let's denote the unknown number as x.

### Step 3: Establish relationships using multiplication
From the series, we can see:
- The number after 8 is x.
- The number after x is 40.
- The number after 40 is 60.
- The number after 60 is also 60.
- The number after 60 is 30.

### Step 4: Analyze the relationship between the known numbers
1. From 40 to 60, we can see that 40 is multiplied by 1.5 to get 60.
2. From 60 to 60, it remains the same, which can be thought of as multiplying by 1.
3. From 60 to 30, we can see that 60 is multiplied by 0.5 to get 30.

### Step 5: Establish the pattern for the unknown number
Now, let's apply the same logic backward to find x:
- If we assume that x is multiplied by 2 to get 40, then:
\[ x \times 2 = 40 \implies x = \frac{40}{2} = 20 \]

### Step 6: Verify the pattern
To confirm, we can check if starting from 20 gives us the same series:
- 8 multiplied by 2.5 gives us 20.
- 20 multiplied by 2 gives us 40.
- 40 multiplied by 1.5 gives us 60.
- 60 multiplied by 1 gives us 60.
- 60 multiplied by 0.5 gives us 30.

### Conclusion
Thus, the value that comes in place of the question mark (?) is **20**.