496, 492, 483, 467, ?

a. 442

b. 431

c. 462

d. 437

**Answer:** a. 442

**Explanation:**

496 - 492 = 4 = 2^{2}

492 - 483 = 9 = 3^{2}

483 - 467 = 16 = 4^{2}

So, the next has to be a difference of 25 = 5^{2}

467 - 25 = 442

CB, HGF, ONML, ?

a. ZYXWV

b. XWVUT

c. VWXYZ

d. YXWV

**Answer:** b. XWVUT

**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

- First two letters are BC in reverse i.e. CB. It is a term of 2 alphabets so next 2 alphabets D and E are skipped.
- Next term is FGH in reverse i.e. HGF. It is a term of 3 alphabets so next 3 alphabets I J and K are skipped.
- Next term is LMNO in reverse i.e. ONML. It is a term of 4 alphabets so next 4 alphabets P Q R and S are skipped.
- Next term should be TUVWX in reverse i.e. XWVUT. It should be 5 alphabets term.

a. B

b. Y

c. Z

d. A

**Answer:** d. A

**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

- Between B and E there are 2 alphabets
- Between E and I there are 3 alphabets
- Between I and N there are 4 alphabets
- Between N and T there are 5 alphabets
- Between T and next alphabet there must 6 alphabets in between
- So next one is A

a. XT

b. YU

c. YV

d. XU

**Answer:** a. XT

**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

**Trace the series in reverse.**

- Between V and S there are 2 alphabets.
- Between S and O there are 3 alphabets.
- Between O and L there are 2 alphabets.
- Between L and H there are 3 alphabets.
- Between H and E there are 2 alphabets.
- Between E and A there are 3 alphabets.
- So, between A and next letter there has to be 2 alphabets. So, it is X.
- And between X and next letter there has to be 3 alphabets. So, it is T.