My name is Carmen
I am a junior in high school

Question:

A college placement test consist of 75 multiple-choice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers one-quarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong?

I am terrible at word problems...thanks for all your time and effort!

Hi Carmen,

You are looking for the number of wrong answers so I need a name for this quantity. I am going to use W for the number of wrong answers. When I read through this question, the other important quantity that I don't know is the number of correct answers. Call this number C. Now read through the question carefully and see if you can write equations for the facts given.

There are 75 questions on the exam and every question was answered so

75 = C + W

Each question has 5 possible answers. I don't see yet how to use this fact so continue with the next sentence.

The exam is scored by subtracting from the number of correct answers one-quarter of a point for each question answered incorrectly.

score = (the number correct) -  1/4(the number of wrong answers) In other words 45 = C -  1/4 W

Solve these two equations for W. Notice that you didn't need to use the fact that each question has 5 possible answers.

Cheers,
Penny
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