Number Series Questions

Given series follows the rule of

1050/2.5 = 420
420/2.5 = 168
168/2.5 = 67.2
so 67.2/2.5 = 26.88

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series
24 - 5 = 19
19 - 5 = 14...

Given number series 131 + 17 = 148 148 + 19 = 167 167 + 23 = 190 190 + 29 = 219 219 + 37 = 256

Here addition is based on 17 + 2= 19, 19 + 4 = 23, 23 + 6 = 29, 29 + 8 = 37

$$\begin{gathered} 2 = 12 + 1 \\ 3 = 22 - 1 \\ 10 = 32 + 1 \\ Now 102 - 1 = 99 \\ 9802 = 992 + 1 \end{gathered}$$

Here the first letter of the group is moved with a gap of one letter, the second letter of the group is backwardness and the third letter of the group is forwardness proceeding like this we get the letter group "JGW"

The pattern of given series is :

5

14 = (5x3) - 1

45 = (14x3) + 3

130 = (45x3) - 5

(?) = (130x3) + 7

=> (?) = 397

1182 = (397x3) - 9

Thus, the missing number is 397.

Here it can be seen that it is not a continuous series.

so take alternative terms.

CGE, FJH, IMK and RNP, OKM,__

Between R and O there is a gap of two letters. so the first letter in the answer is L.Proceding like this the answer is LHJ