What should come in place of question mark (?) in the following number series.
5 4 7 20 79 ?

Options

A. 408
B. 372
C. 394
D. 350

Answer

To find the missing number in the series 5, 4, 7, 20, 79, ?, we will analyze the pattern of the series step by step.

### Step 1: Identify the pattern
- The series starts with 5, then goes to 4, then to 7, then to 20, and finally to 79.
- We will look for a relationship between consecutive numbers.

### Step 2: Calculate the first transition (5 to 4)
- From 5 to 4:
\[ 5 \times 1 - 1 = 4 \]

### Step 3: Calculate the second transition (4 to 7)
- From 4 to 7:
\[ 4 \times 2 - 1 = 8 - 1 = 7 \]

### Step 4: Calculate the third transition (7 to 20)
- From 7 to 20:
\[ 7 \times 3 - 1 = 21 - 1 = 20 \]

### Step 5: Calculate the fourth transition (20 to 79)
- From 20 to 79:
\[ 20 \times 4 - 1 = 80 - 1 = 79 \]

### Step 6: Calculate the fifth transition (79 to ?)
- Now, we need to find the next number after 79:
\[ 79 \times 5 - 1 = 395 - 1 = 394 \]

### Conclusion
Thus, the number that should come in place of the question mark (?) is **394**.

### Final Answer
The answer is **394**.

---