Sagot :
Part A
I'm assuming you meant to say "you can get 1 point for each correct answer".
x = number of correct answers
y = number of incorrect answers
1x = points from the correct answers
2y = points you lose from the incorrect answers
1x-2y = total points
Answer: x-2y
============================================
Part B
Tim got x = 22 questions correct and y = 3 incorrect.
So,
x-2y = 22-2*3 = 22-6 = 16
Answer: 16
============================================
Side note: If Tim got a score of 16 out of 22+3 = 25, then the percentage is 16/25 = 0.64 = 64%. It appears that getting even a few wrong answers takes a pretty hefty toll on the final percentage.
Answer:
Below!
Solution for Part A:
To create an expression for this, we will need to recall:
- 1 correct answer = 1 point
- 1 Incorrect answer = -2 points
Using these clues, we know that the expression is c - 2w.
Solution for Part B:
We know that:
- Total points earned = c - 2w
- c = Number of correct answers
- w = Number of incorrect answers
Work:
- 22 - 2(3) = Total points earned by Tim
- => 22 - 6 = Total points earned by Tim
- => 16 = Total points earned by Tim
Hence, Tim earned 16 points in total.