Solutions for Number series

1.      544,509,474,439,___

544-509=35

509-474=35

474-439=35

439-x=35

So, 439-35=404

2.      2,6,18,54,___

2*3=6

6*3=18

18*3=54

54*3=162

3.      8,6,9,23,87,___

8*1-2=6

6*2-3=9

9*3-4=23

23*4-5=87

87*5-6=429

4.      1,9,17,33,49,73,___

1+8=9

9+8=17

17+16=33

33+16=49

49+24=73

73+24=97

5.      5,9,17,29,45,___

5+4=9

9+8=17

17+12=29

29+16=45

45+20=65

6.      121,225,361,___

121= 11²

225= 15²

361= 19²

The diff of squares are 4

So 23²= 529

7.      0,2,8,14,___,34

1*1-1=0

2*2-2=2

3*3-1=8

4*4-2=14

5*5-1=24

6*6-2=34

8.       3,6,18,72,___

3*2=6

6*3=18

18*4=72

72*5=360

9.      2,15,41,80,__

2+13=15

15+26=41

41+39=80

80+52=132

10.  7: 56:: 9:?

7*8=56

9*10=90

11.  10: 26:: 50:?

3*3+1=10

5*5+1=26

7*7+1=50

9*9+1=82

12.  28:39 ::52:?

5*5+3=28

6*6+3=39

7*7+3=52

8*8+3=67

13.  6522: 114:: 2859: ?

6522 => 6+5=11, 2+2=4 =>114

2859=> 2+8=10, 5+9=>14 =>1014

14.  4,8,9,16,___

All are Perfect squares Except  8

( 2²=4, 3²=9^,, 4² = 16)

                                                                                              

15.  37,47,57,67 Odd man out

57 is not prime where as others are prime

16.  24,60,124,210 Odd man out

Except 124 others are multiples of 3

17.  144,169,256,324 Odd man out

144=12²

169=13²

256=16²

324=18²

Here except 13 others are even numbers, so 169

18.  121, 441, 991, 1681 Odd man out

Except 991 others are squares

19.  125,343,729,2197 Odd man out

5³=125

7³=343

9³=729

13³=2197

Except 9 others are prime so 729

20.  3587: 1556:: 8734:?

3*5=15

8*7=56

Similarly 8*7=56, 3*4=12 so 5612

21.  2,7,24,77,___

3^1-1=2

3^2-2=7

3^3-3=24

3^4-4=77

3^5-5=238

22.  3,4.5,9,22.5,___

3*1.5=4.5

4.5*2=9

9*2.5=22.5

22.5*3=67.5

23.  9,19,40,83,__

9*2+1=19

19*2+2=40

40*2+3=83

83*2+4=170

24.  55,19,44,12,33,7,___

Alternative series 55 – 44 – 33 - ?

Difference 11 so 33-11 =22

25.  46: 574 :: 56: ?

4*6=24

24*24=574

So 5*6= 30

30*30 = 900