Number Series Questions

Which one is wrong in the given series?

49 36 25 18 9 4

In the following question, select the missing number from the given series.

43, 58, 88, 133, ?, 268

In the following question, select the missing number from the given series.

831, 842, 853, 864, 875, ?

In the following question, select the missing number from the given series.

23, 23, 46, 138, 552, ?

Which of the following terms follows the trend of the given list?

XYXYXYxY, XYXYXyXY, XYXYxYXY, XYXyXYXY, XYxYXYXY,  _______________.

In the following question, select the missing number from the given series.

470, 465, 460, 455, ?, 445

In the following question, select the missing number from the given series.

46, 41, 35, 30, ?, 19, 13

In the following question, select the missing number from the given series.

52, 41, 32, 25, ?, 17