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In a class test(3+) marks are given for every correct answer and (-2) marks are given for every incorrect answer (-2) marks are given for every incorrect answer and no marks for not attempting any question. (i) Radhika scored 20 marks. If she got 12 correct answers, how many questions has she attempted incorrectly? (ii) Mohini scores -5 marks in this test, though she has got 7 correct answers.How many questions has she attempted incorrectly?

Answer :

MrRoyalgo

Radhika attempted 8 questions incorrectly, while Mohini attempted 13 questions incorrectly.

The number of Radhika's incorrect attempt

The given parameters are:

Correct = +3

Wrong = -2

Let the correct attempt be x and the incorrect attempt be y.

The equation that represents the total score is:

Total = 3x - 2y

She scored a total of 20.

So, we have:

3x - 2y = 20

She got 12 correctly.

So, we have:

3 * 12 - 2y = 20

Evaluate the product

36 - 2y = 20

Subtract 36 from both sides

-2y = -16

Divide by -2

y = 8

Hence, Radhika attempted 8 questions incorrectly.

The number of Mohini's incorrect attempt

In (a), we have the equation that represents the total score is:

Total = 3x - 2y

She scored a total of -5

So, we have:

3x - 2y = -5

She got 7 correctly.

So, we have:

3 * 7 - 2y = -5

Evaluate the product

21 - 2y = -5

Subtract 21 from both sides

-2y = -26

Divide by -2

y = 13

Hence, Mohini attempted 13 questions incorrectly.

Read more about linear equations at:

https://brainly.com/question/14323743

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