Here it follows a pattern that

4

4 x 1.5 = 6

6 x 2 = 12

12 x 2.5 = 30

30 x 3 = 90 not equals to 81

90 x 3.5 = 315

Hence the odd one in the series is 81.

2

2 x 1.5 + 1 = 4

4 x 1.5 + 1 = 7 (not equal to 8)

7 x 1.5 + 1 = 11.5

11.5 x 1.5 + 1 = 18.25

18.25 x 1.5 + 1 = 28.375

In each term second two numbers are multiples of the first number. But in 4-15-24 15 is not multiple of 4.

The given series pattern follows

17       9       10       18.5       35       90

× 0.5 + 0.5,   × 1 + 1,   × 1.5 + 1.5,   × 2 + 2,   × 2.5 + 2.5

So here

17×0.5 + 0.5 = 9

9×1 + 1 = 10

10×1.5 + 1.5 = 16.5

16.5×2 + 2 = 35

35×2.5 + 2.5 = 90

Here the odd man in the given series is 18.5

Here the series follows the pattern that, product of succesive prime numbers i.e,

2 × 3 = 6

3 × 5 = 15

5 × 7 = 35

7 × 11 = 77

11 × 13 = 143

13 × 17 = 221

17 × 19 = 323

So here in place of 77 the number 63 is written.

So the wrong number is 63.

The sum of the digits in 708, 618 and 816 is 15, but not in 392.

The Given number series 3, 6.5, 14, 29, 64, 136 follows a pattern that

3

3 x 2 + 0.5 = 6.5

6.5 x 2 + 1 = 14

14 x 2 + 2 = 30 ≠≠29

30 x 2 + 4 = 64

64 x 2 + 8 = 136

Thus the wrong number in the series is 29

The given series follows the pattern that,

18, 97, 26, 91, ?, 83

=> 18 + 8 = 26

=> 97 – 8 = 91

=> 26 + 8 = 34

=> 91 – 8 = 83

Hence, the missing number is 34.

The series given follow the pattern

+2, +2+4, +2+4+6, +2+4+6+8, +2+4+6+8+10,…

Here ? = 7 + 2 + 4 = 13.

Except Granite all other options belong to the group of precious stones.

The Sum of the digits in each number, Except 324 is 10.

The terms are alternatively multiplied by 1.5 and divided by 3. However, 18.5 does not satisfy it.

1, 1 + 1² = 2, 2 + 2² = 6, 6 + 3² = 15, 15 + 4² = 31, 31 + 5² = 56, 56 + 6² = 92

Last number of given series must be 92 not 91.

(1*1)+1 , (2*2)+1 , (3*3)+1 , (4*4)+1 , (5*5)+1 , (6*6)+1 , (7*7)+1 , (8*8)+1

But, 64 is out of pattern.