Number Series Questions

In this series, the third letter is repeated as the first letter of the next segment. The middle letter, A, remains static. The third letters are in alphabetical order, beginning with R.

The given number series is 18, 90, 450, 2250, ?

18

18 x 5 = 90

90 x 5 = 450

450 x 5 = 2250

2250 x 5 = 11250

Hence, the next number in the given series is 11250.

The given number series 999, 990, 998, 991, 997, 992, ?

It follows a pattern that,

999

999 - 9 = 990

990 + 8 = 998

998 - 7 = 991

991 + 6 = 997

997 - 5 = 992

992 + 4 = 996

Hence, the next number in the given number series is 996.

The given number series is 200, 200, 100, 300, 75, ?

It follows a pattern that,

200

200 x 1 = 200

200 / 2 = 100

100 x 3 = 300

300 / 4 = 75

75 x 5 = 375

Hence, the next number in the given number sequence is 375.

The given series follows a pattern of +19, x19, +17, x17, +15, x15,...

Here the number which is to be replaced in ? is

41310+15=41325.