Question

A middle school is expanding to open a high school next year, doubling the total number of students. The school keeps a database in which each student's unique ID number is stored as an 8 bit number called studentID. Before the arrival of the new students almost every 8 bit number has already been assigned to a student. Of the options provided below, which is the smallest change to the way studentID is represented necessary to ensure each incoming student receives a unique ID?

A. Add a bit to studentID to double the number of IDs that the database can represent.
B. Double the number of bits in studentID to double the number of IDs that the database can represent
C. Keep using an 8-bit number for studentID but reserve the first bit to indicate middle school or high school.
D. Remove a bit from studentID to make room for incoming students.

Answer 1

A. Add a bit to studentID to double the number of IDs that the database can represent.

Step-by-step explanation:

Each time a bit is added, the number of possible values is doubled.

For example, 1 bit there are only two possible values: 0 or 1

2 bits, 4 values: 00, 01, 10, 11

3 bits, 8 values...

So the correct answer is:

A. Add a bit to studentID to double the number of IDs that the database can represent.