Question

Write a boolean expression that is true if and only if the variable score is not in the range 200–800, inclusive. a. score < 200 or score > 800 b. score >= 200 and score <= 800 c. not (score >= 200 and score <= 800)

Answer 1

A boolean expression that is true if and only if the variable score is not in the range 200–800, inclusive, is 'score < 200 or score > 800'.

Step-by-step explanation:

To write a boolean expression that is true if and only if the variable score is not in the range 200–800, inclusive, we have to consider the logic required to capture values outside this range. The correct expression is score < 200 or score > 800.

This is because both conditions being true simultaneously would mean that score is either below 200 or above 800, which are the two scenarios that put the score outside the given range. Option b, score >= 200 and score <= 800, describes scores within the range.

Option c, not (score >= 200 and score <= 800), is logically equivalent to option a, so it also represents the correct boolean expression for the desired condition as it negates the range 200–800, resulting in the score being outside that range.