Number Series Questions

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.

$$\begin{gathered} 63+6=222 \\ \end{gathered}$$ 

Similarly , 253+25=15650

The given sequence a combination of two series:
I)Z, W, T, Q, ?      and      II)S, O, K, G, ?

The pattern I is
Z - 3 = W
W - 3 = T
T - 3 = Q
Q - 3 = N

The pattern in II is
S - 4 = O
O - 4 = K
K - 4 = G
G - 4 = C

Because the letters are the same, concentrate on the number series, which is a simple 2, 3, 4, 5, 6 series, and follows each letter in order.

The given number series follows a pattern that,

$$\begin{gathered} 19 + 12 = 20 (not 21) \\ 20 + 22 = 24 \\ 24 + 32 = 33 \\ 33 + 42 = 49 \\ 49 + 52 = 74 \end{gathered}$$

Hence, the odd number in the given number series is 21.

The given number series is 8, 11, 19, 23, 32, ?

It follows a pattern that

8 + 11 = 19

11 + 12 = 23

19 + 13 = 32

23 + 14 = 37

32 + 15 = 47

....

Hence, the next number in the given series = 37.

By trial and error method from the given options,

'1' satisfies the above given equation.

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.