Answer :

Final answer:

The next number in the series 12, 35, 81, 173, 357 is 725, found by identifying that each difference between consecutive numbers is double the previous difference.

Explanation:

To determine the next number in the series 12, 35, 81, 173, 357, we need to analyze the pattern of increments between the numbers and identify a consistent rule or formula. Let's look at the differences between consecutive numbers:

  • 35 - 12 = 23
  • 81 - 35 = 46
  • 173 - 81 = 92
  • 357 - 173 = 184

Each difference is exactly double the previous difference. If the pattern continues, the next difference in the series should be double 184, which is 368.

Now, we add this difference to the last number in the series to find the next number:

357 + 368 = 725

Therefore, the next number in the series is 725.