A teacher decides to award the following points:
5 points for each correct answer.
-2 for each incorrect answer.
-4 for each unanswered question.
There were 20 questions on the exam.
What is the score of the student who answers all the questions correctly, except for 4 questions that are left unanswered?
To solve this problem, we'll follow these steps:
- Step 1: Identify the given information
- Step 2: Calculate the number of correct answers
- Step 3: Calculate the score from correct answers
- Step 4: Calculate the score from unanswered questions
- Step 5: Sum the contributions to get the total score
Now, let's work through each step:
Step 1: Identify the given information
The problem states there are 20 total questions, with 5 points for each correct, -2 for each incorrect, and -4 points for each unanswered question. The student left 4 questions unanswered.
Step 2: Calculate the number of correct answers
Since the student answered all questions except 4, the correct number of answers is 20 - 4 = 16.
Step 3: Calculate the score from correct answers
The score for correct answers is 16×5=80 points.
Step 4: Calculate the score from unanswered questions
We have 4 unanswered questions, contributing 4×(−4)=−16 points.
Step 5: Sum the contributions to get the total score
Add the scores from the correct and unanswered questions: 80+(−16)=64.
Therefore, the solution to the problem is 64.