7 8 16 43 ?

a. 107

b. 96

c. 86

d. 103

**Answer:** a. 107

**Explanation:**

8 - 7 = 1

16 - 8 = 8

43 -16 = 27

1, 8, 27 are cubes of 1, 2 and 3

So next difference must be cube of 4

So, ? - 43 = 4^{3} = 64

So, ? = 64+43 = 107

a. 361

b. 400

c. 420

d. 441

**Answer:** b. 400

**Explanation:**

Here we see ups and downs in the series so there is a chance of 2 separate series

We can have 20 24 30 38 as one series

And 4 64 196 as other series.

Both series occur alternately so next term has to be of the second series.

In first series difference is

24 - 20 = 4

30 - 24 = 6

38 - 30 = 8

So, difference increases by 2

In second series, We see they are squares i.e. 2^{2}, 8^{2}, 14^{2}

8-2 = 6

14-8 = 6

So next number, ? - 14 has to be = 6

So, ? = 14+6 = 20

So next term is 20^{2} = 400

a. VN

b. UN

c. TM

d. VO

**Answer:** a. VN

**Explanation:**

Alphabet Series - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Here the first letters of the terms is C, H, N

H is 5^{th} letter from C

N is 6^{th} letter from H

So next has to be 7^{th} letter from N i.e. V

In the second letters we have Z, U, Q

U is 5^{th} letter from Z

Q is 4^{th} letter from U

So next has to be 3^{rd} letter from Q i.e. N

AN13 , BZ24 , CO12 , DY21 , ?

a. EP18

b. EX18

c. FX10

d. EP11

**Answer:** d. EP11

**Explanation:**

**Alphabets and their positions**

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |

- First letters of each term are A, B, C, D. So, in answer first letter should be E.
- Second letters are N, Z, O, Y. We can observe there are alternately 2 series N, O, etc. and Z, Y, etc.
- So next has to be P which comes after O.
- In many alphanumeric series, numbers are mostly related to the positions of the letters.
- See the first term, A has position 1. N has position 14. 14 -1 = 13
- Similarly, B has position 2. Z has 26. 26 - 2 = 24
- In ? we have EP. E has position 5. P has 16. 16 - 5 = 11