Multiple choice

If A, B, C, ___, Z represent operands and +, -, *, / ­represent operators, which of the following does not represent a valid expression?

  1. A B - C + D E F - + ­
    • + A - * ­ B C D / + E F * G H I
    • - ­ A B C * D * * E F G

  4. A B C D E - + ­ * E F *
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Postfix expressions require a specific balance of operands and operators. Option D has too many operands relative to the number of operators, making it an invalid postfix expression.

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