What should come in place of question mark(?) in the following number series ?
4 3 4 7 15 ?

Options

A. 38.5
B. 40
C. 45
D. 37.5

Answer

To solve the number series 4, 3, 4, 7, 15, ?, we need to identify the pattern in the series. Let's break it down step by step.

### Step 1: Analyze the series
We have the series: 4, 3, 4, 7, 15, ?

### Step 2: Identify the operations
- The first number is 4.
- The second number is 3, which can be obtained by multiplying 4 by 0.5 and then adding 1:
\[ 4 \times 0.5 + 1 = 2 + 1 = 3 \]

### Step 3: Continue the pattern
- The third number is 4, which can be obtained from the second number:
\[ 3 \times 1 + 1 = 3 + 1 = 4 \]

- The fourth number is 7, which can be obtained from the third number:
\[ 4 \times 1.5 + 1 = 6 + 1 = 7 \]

### Step 4: Find the next number
- The fifth number is 15, which can be obtained from the fourth number:
\[ 7 \times 2 + 1 = 14 + 1 = 15 \]

### Step 5: Apply the same pattern to find the question mark
- To find the next number (?), we will apply the same pattern:
\[ 15 \times 2.5 + 1 = 37.5 + 1 = 38.5 \]

### Conclusion
The number that should come in place of the question mark (?) is **38.5**.