In a code language, 'SPACE' is written as '5-91' and 'ROTTEN' is written as '6-70'. How will 'MEAN' be written in that language?

4-75

1   2    3    4   5    6   7     8    9  10  11  12  13

 A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

*********************************************

THE LOGIC FOLLOWED HERE IS :

NO. OF LETTER = IST NUMBER

SUM OF OPPOSITE POSITIONAL VALUE OF GIVEN ALPHABET = IIND NUMBER

AS

ROTTEN  = 6 LETTERS

R → (OPPOSITE POSITIONAL VALUE) → 9

O → (OPPOSITE POSITIONAL VALUE) → 12

T → (OPPOSITE POSITIONAL VALUE) → 7

T → (OPPOSITE POSITIONAL VALUE) → 7

E → (OPPOSITE POSITIONAL VALUE) → 22

N → (OPPOSITE POSITIONAL VALUE) → 13

9 + 12 + 7 +  7 + 22 + 13  = 70

6 -70

SIMILARLY

MEAN = NO. OF LETTERS = 4

M → (OPPOSITE POSITIONAL VALUE) → 14

E → (OPPOSITE POSITIONAL VALUE) → 22

A → (OPPOSITE POSITIONAL VALUE) → 26

N → (OPPOSITE POSITIONAL VALUE) → 13

14 + 22  + 26 + 13 = 75

4 - 75