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10 votes
10 votes
In a class test (+ 5) marks are given for every correct answer and (-3) marks are given for every incorrect answer.

a) Anu gets 8 correct answer and 12 incorrect answers what is her score?
b) Sam answered all the questions and scored 28 marks though he got 11 correct answers.

How many incorrect answers had he attempted?

● Please answer my question and I do not need any links​

User Ethan Liou
by
2.2k points

2 Answers

14 votes
14 votes

Answer:

He or she attempted 9 incorrect answers

Explanation:

User Rampuriyaaa
by
3.1k points
7 votes
7 votes

Answer:

a. 4 marks b. 9 questions

Explanation:

a) Anu gets 8 correct answer and 12 incorrect answers what is her score?

Since Anu got 8 correct answer and 12 incorrect answers, and + 5 marks is given for every correct answer and (-3) marks are given for every incorrect answer, the total score for correct answers is number of correct answer × marks for correct answer = 8 × (+ 5) = 40.

Also, the total score for incorrect answers is number of incorrect answer × marks for incorrect answer = 12 × (- 3) = -36.

Anu's total score = total score for correct answers + total score for incorrect answers = 40 + (-36) = 40 - 36 = 4 marks.

So, Anu scored 4 marks.

b) Sam answered all the questions and scored 28 marks though he got 11 correct answers. How many incorrect answers had he attempted?

Let x be the number of incorrect answers. Since the marks for incorrect answers is -3, then his total score for incorrect answers is -3x.

Since Sam got 11 correct answers and is given + 5 marks for each correct answer, then his total score for correct answers is 11 × (+5) = +55.

Since he gets a total of 28 marks, we have that total score for incorrect answer + total score for correct answer = 28.

So, -3x + 55 = 28

Solving for x, we have

-3x = 28 - 55

-3x = -27

x = -27/-3

x = 9

Since x = 9, Sam attempted 9 incorrect questions.

.

User Yogesh Chawla
by
3.3k points