Write a function that takes as input a string and returns the number of occurrences of each letter. Remember that you should count the letter if it is uppercase or lowercase so make sure your program takes that into consideration.

What is a number system, and what is the total number of digits used in this system called? a number system is a system that uses different (options: a) numbers b) symbols c) codes d) digits e) alphabets) to represent different numbers. the total number of digits used in a number system is known as its (options: 1) processor 2) converter 3) radix 4) least significant digit 5) most significant digit)