Sure! Let's break down the question step-by-step to find Sonia's final score:
1. Determine the number of correct and incorrect answers:
- Sonia answered 7 questions correctly.
- Sonia answered 3 questions incorrectly.
2. Identify the marks awarded for correct and incorrect answers:
- For each correct answer, Sonia earns 3 marks.
- For each incorrect answer, Sonia loses 1 mark.
3. Calculate the total score from correct answers:
- For 7 correct answers, the total score would be:
[tex]\[
7 \text{ (correct answers)} \times 3 \text{ (marks per correct answer)} = 21 \text{ marks}
\][/tex]
4. Calculate the total penalty from incorrect answers:
- For 3 incorrect answers, the total penalty would be:
[tex]\[
3 \text{ (incorrect answers)} \times (-1) \text{ (marks per incorrect answer)} = -3 \text{ marks}
\][/tex]
5. Determine the final score by combining the scores from correct and incorrect answers:
- Add the total score from correct answers and the total penalty from incorrect answers:
[tex]\[
21 \text{ marks (from correct answers)} + (-3 \text{ marks (from incorrect answers)}) = 18 \text{ marks}
\][/tex]
Therefore, Sonia's final score in the quiz is 18 marks.