Example 6: Reverse positional sum coding
Last Updated On: Sat Aug 29 2026Given Data
- In a certain code language, 'ZIP' is written as 30.
Question
How will 'CAT' be coded in that language?
Answer
57.
Solution
- Find the reverse alphabetical rank (27 - forward rank) for 'ZIP':
- Z = 27 - 26 = 1
- I = 27 - 9 = 18
- P = 27 - 16 = 11
- Sum of reverse ranks = 1 + 18 + 11 = 30.
- Apply the reverse rank sum rule to 'CAT':
- C = 27 - 3 = 24
- A = 27 - 1 = 26
- T = 27 - 20 = 7
- Sum = 24 + 26 + 7 = 57.
- Therefore, 'CAT' is coded as 57.