Find the odd letter/word from the given alternatives.

Correct Answer: 21 months

Explanation:

Total savings = 200 + 200 + 200 + 240 + 280 + ... to n months = 11040

= 120 + 80 + 160 + 40 + 200 + 240 + ....n terms
= 40 + 80 + 120 + 160 + 200 + 240 + ...n terms
= n/2[2a + (n-1)d] + 80 + 40 = 11040
= n/2[240 + (n-1)40] = 10920
= n[6+n-1] = 546
= n[n+5] = 546
n = 21

Correct Answer: 82.5

Explanation:

The given series 

 

12   24   26.5   79.5   ?   330 follows a pattern that,

 

12 x 2 = 24

 

24 + 2.5 = 26.5

 

26.5 x 3 = 79.5

 

79.5 + 3 = 82.5

 

82.5 x 4 = 330

 

Hence, the missing number is 82.5

Correct Answer: 29

Explanation:

Here the given number series follows a pattern of two alternate series.

1. 7 19 31 ...(Difference of 12)

2. 9 18 27 ...(Difference of 9)

Here the odd number is 29 instead of 27

And the next number is 31 + 12 = 43 & 27 + 9 = 36

 

Correct Answer: 10

Explanation:

Given nuber series is 15, 30, ? , 40, 8, 48 

Here the number series follows a pattern that

15

15 x 2 = 30

30  ÷ 3 = 10

10 x 4 = 40

40  ÷ 5 = 8

8 x 6 = 48

Hence, the missing number in the series is 10.

Correct Answer: 145

Explanation:

4       30       ?     1440       7195      71940

 

Here the given series follows a pattern of

 

4

 

4 x 10 - 10 = 30

 

30 x 5 - 5  = 145

 

145 x 10 - 10 = 1440

 

1440 x 5 - 5 = 7195

 

7195 x 10 - 10 = 71940

 

Hence, the missing number is 145

Correct Answer: 54055

Explanation:

Here the given series follows a pattern that, multiplying the number with odd numbers in decreasing order starting with 13. That is,

 

6 × 13 = 78

 

65 × 11 = 858

 

858 × 9 = 7722

 

7722 × 7 = 54054

 

54054 × 5 = 270270

 

Hence, the wrong number is 54055

Correct Answer: 245

Explanation:

Given 311   230   294   ?   281   256

 

311 - (9x9) = 230

 

230 + (8x8) = 294

 

294 - (7x7) = 245

 

245 + (6x6) = 281

 

281 - (5x5) = 256

 

Hence, the missing number in the given series is 245.

Correct Answer: 32

Explanation:

Here the given series follows a pattern that,

2² - 0 = 4  

3² - 1 = 8  

4² - 2 = 14

5² - 3 = 22

6² - 4 = 32

Hence, the missing number is 32

 

 

Method 2 ::

The difference between 4 and 8 is 4, the difference between 8 and 14 is 6, the difference between 14 and 22 is 8. So the next difference between 22 and the next number will be 10 since it follows (4,6,8,10 - add +2 each time)

Hence, 22 + 10 = 32 is the missing number.

Correct Answer: 1962

Explanation:

Arithmetic Series ::

 

An Arithmetic Series is a series of numbers in which each term increases by a constant amount.

 

How to find the sum of the Arithmetic Sequence or Series for the given Series ::

 

When the series contains a large amount of numbers, its impractical to add manually. You can quickly find the sum of any arithmetic sequence by multiplying the average of the first and last term by the number of terms in the sequence.

 

That is given by  S n = n ( a 1 + a n ) 2 Where n = number of terms, a1 = first term, an = last term

 

Here Last term is given by  a n = a 1 + n - 1 d where d = common difference

 

Now given Arithmetic Series is 

 

2, 5, 8, 11,...

 

Here a1 = 2,  d = 3, n = 36 

 

Now,  $$\begin{gathered} a n = a 1 + n - 1 d \\ a 36 = 2 + 36 - 1 3 = 105 + 2 = 107 \end{gathered}$$

 

Now, Sum to 36 terms is given by

 

S 36 = 36 ( 2 + 107 ) 2 = 36 x 109 2 = 3924 2 = 1962

 

 

 

Therefore, Sum to 36 terms of the series 2, 5, 8, 11,... is 1962.

Correct Answer: 156

Explanation:

Here the given series 7  18  42  94  204 follows a pattern that, 

7

7 ×2+4 = 18

18 ×2+6 = 42

42 ×2+10 = 94

94 ×2+16 = 204

Similarly,

4

4 ×2+4 = 12

12 ×2+6 = 30

30 ×2+10 = 70

70 ×2+16 = 156

Hence, the value of P = 156.