Q. If it is desired to store English-language writing with 1 byte representing each letter, find the minimum number of bits per byte that could be used.
Ans.
For the 26 letters in the English alphabet, we must have 2N ≥ 26, where N is the number of bits per byte. N being an integer, the smallest possible value for N is 5. One can represent the letter A by 00000, B by 00001, and so on up to Z by 11001; the remaining six combinations could be used for representing punctuation marks or spaces. This is, in fact, the method by which letters are represented in teletype systems.
If one wants to store capital English-language letters also, there will be 52 letters instead of 26; in such a case 6-bit bytes would have to be used.