NUMBER SERIES

 NUMBER SERIES

When try to solve these type of question,First thing to do is How the series was move from the first letter.
The movement was may slow or medium or high.
Slow-addition/subtraction,multiplication with small numbers or fractions or decimal values,division.
Medium-addition with previous term or addition with some constant or doubling of that constant.
High-square,cube,big number multiplication.
THE PATTERNS ARE:
ADD/SUB-Even numbers.(2,4,6,...)
ADD/SUB-Odd numbers.(1,3,5,7,..)
ADD/SUB-Ascending order(1,2,3,...).
ADD/SUB-Descending order(5,4,3,2....).
ADD/SUB-Square(1,4,9,16,25,..).
ADD/SUB-Cube(1,8,27,64,...).
PRIME NUMBER (The number divide by it self and one)
Eg: 2 it div by 1 and 2 only,
Eg: 4 it div by 2,4,1 so it's not a prime.
1 is neither or nor a prime.
ALTERNATE:
ADD AND SUB:(....,+3,-2,+1,-0),(+3,-3,+3,-3,..) ,(+3,-5,+7,-9,..),...
FRACTION:
If you find a series with decimal value it operated with a fraction or multiply by decimal or division.
     

QUESTION AND ANSWER

1) 15 18 16 19 17 20 ?

15+3=18

18-2=16

16+3=19

19-2=17

17+3=20

 Alternate of (+3 and -2)

so 20-2=18

2) 32 49 83 151 287 559 ?

32+17=49

49+34=83

83+68=1515

151+136=287

287+272=559

Doubling of Previous number added with series(17,2*17,2*34,2*68,2*136,2*272)

2*272=544==>559+544=1103.

3)462 552 650 756 870 992 ?

462+90=552

552+98=650

650+106=756

756+114=870

870+122=992

The first two number difference is 90 and the second is 98 the 8 was added with previous number.

992+(122+8)=992+130= 1122

4) 2 7 14 23 ? 47

2+5=7

7+7=14

14+9=23

23+11=34

34+13=47

Odd number addition with each digit(5,7,9,11,13)

5) 24 ? 109 134 150 154 

24+49=73

73+36=109

109+25=134

134+16=150

150+9=159

Square value added with descending order (7^2=49,6^2=36,5^2=25,4^=16,3^2=9).

6) 3 5 15 ? 1125 84375

3*5=15

15*5=75

75*5=1125

1125*5=84375

Multiplication of 5 with previous and current number.

7)1 ? 27 64 125

1^3=1

2^3=8

3^3=27

4^3=64

5^=125

Cube of Ascending number.

8) 2 5 7 12 19 31 50 ?

2+3=5

5+2=7

7+5=13

12+7=19

19+12=31

31+19=50

Adding current number with previous term. 

50+31= 81

 9) 104 153 189 214 ?

104+7^2=153

153+6^2=189

189+5^2=214

Each term  add with  square of descending number.

214+4^2=230

10) 1050 420 168 67.2 26.88 10.752 ?

1050*0.4=420

420*0.4=168

168*0.4= 67.2 

Multiplication with constant Decimal number.

10.752*0.4=4.008