Answer:
<h2>She needs 17 correct answers.</h2>
Step-by-step explanation:
Givens
- You score -5 points each time you guess the correct answer.
- Marna must have a score less than -80 points to win.
Now, let's be
the total number of correct answers. If you score -5 points per correct answer, that means
.
So, we know that Marna must score LESS THAN -80 points, that can be expressed as

Therefore, Marna need 17 correct answer to win the game. Remember that she needs less than -80 points, so with 16 answer she's gonna get barely -80, which is not enough to win the game.