The following question is based on the following 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 If the first and second letters interchange their positions and similarly the third and the fourth letters, the fifth and the sixth letters and so on, which letter will be the seventeenth from your right ?

C. I

The following question is based on the following 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 If the given alphabet is arranged in reverse order, which letter will be the eighth letter to the left of the seventh letter counting from the right end ?

B. O

The following question is based on the following 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 If the given sequence of letters is written in a reverse order, which of the following will be the seventh letter to the left of eighth letter from your right ?  

C. O

The following question is based on the following 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 Which letter is sixteenth to the right of the letter which is fourth to the left of I ?

C. U

The following question is based on the following 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 Which letter is exactly midway between H and S in the given alphabet ?

E. NO SUCH LETTER