87) The 2 ′s complements of binary number 010111.1100 is

88) Consider a number system with radix 20. The excess code that is necessary or its equivalent binary coded representation is

89) A decimal number has 30 digits. Approximately, how many digits would the binary representation have?

90) A circuit produces 1 ′s complement of the input word, one application is binary subtraction. It is called

91) The most commonly used character codes for transmission is