What should come in place of the question mark (?) in the following number series ?
`583" "572" "546" "505" "449" "?`

Options

A. 387
B. 478
C. 487
D. 378

Answer

To find the missing number in the series 583, 572, 546, 505, 449, we need to analyze the differences between consecutive numbers.

1. **Calculate the differences between consecutive terms:**
- 583 - 572 = 11
- 572 - 546 = 26
- 546 - 505 = 41
- 505 - 449 = 56

So, the differences are: 11, 26, 41, 56.

2. **Identify the pattern in the differences:**
- The differences themselves seem to increase by a constant amount.
- 26 - 11 = 15
- 41 - 26 = 15
- 56 - 41 = 15

This shows that the differences are increasing by 15 each time.

3. **Calculate the next difference:**
- The next difference after 56 would be 56 + 15 = 71.

4. **Subtract this difference from the last term in the series:**
- 449 - 71 = 378.

Thus, the number that should come in place of the question mark (?) is **378**.