Question

which statement about using relational comparison operators is correct?
○ a. if salesrate is assigned a numeric value, the boolean expression salesrate == .8 is a trivial expression.
○ b. the boolean expression currentsalary == maxpay is not permitted because you cannot compare a variable to a named constant.
○ c. if totalprice is assigned a numeric value, the boolean expression totalprice == \35\ is incorrect because the operands have different data types.
○ d. if color is assigned the value \green\, the boolean expression color == \green\ will always evaluate to true.

Explanation:

• Option a: A trivial expression would be something like x = x, but taxRate = .8 is an assignment (if using = for assignment) or a comparison of a variable to a constant, not trivial in the typical sense.
• Option b: Comparing a variable to a named constant (like MAXNUM) is permitted in most programming/logic contexts.
• Option c: If totalPrice is numeric and "35" is a string, comparing them with = (for equality) is incorrect because their data types differ (numeric vs. string), so this statement is correct.
• Option d: String comparison is case - sensitive in most cases. So if color is "green" and we compare to "Green", the case difference means it will evaluate to false, not always true.

Answer:

c. If totalPrice is assigned a numeric value, the Boolean expression totalPrice = "35" is incorrect because the operands have different data types.