Question

Q4. In a test (+5) marks are given for every correct answer and (-2) marks are given

for every incorrect answer.

(i) Neha answered all the questions and scored 30 marks though she got 10 correct

answers.

(ii) Ajay also answered all the questions and scored (-12) marks though he got 4

correct answers. How many incorrect answers had they attempted?

answer this I will mark you as a brainlist​

Answer 1

Let there were total x questions .

Radhika answered all the question .

So Radhika answered x questions .

So no. of questions incorrectly answered by her are x-10

So she got 10 correct answers and x-10 wrong answers .

As +5 are provided for every correct answer and -2 for every wrong answer , the total marks she will get are --

5(10) + (-2)(x-10) = 50 - 2x +20 = 70 - 2x

Now , the total marks she got are 30

So, 70 - 2x =30

70 - 30 = 2x

40 = 2x

20 = x

So, total no. of questions she answered are 20.

So, she got (20-10) wrong answeres i.e. 10 wrong answers .

Let the total no. of question for Jay be x

He got 4 correct questions

So he got x-4 incorrect questions

Total marks he got --

5(4) + (-2)(x-4) = 20 - 2x + 8 = 28 -2x

Now he got a total of -12 marks

28 - 2x = -12

Solving this equations we get x =20

So he answered 20 questions in total .

He got (20-4) wrong answers i.e. 16 wrong answers.

Answer 2

Given:

Marks given for every correct answer = 5

Marks deducted for every wrong answer = 2

Question:

(i) Neha answered all the questions and scored 30 marks though she got 10 correct

answers.

How many incorrect answers had she attempted?

Solution:

Correct answers = 10

Total marks scored = 30

If, marks scored for correct answers = 10×5 = 50

then 20 marks is lost for wrong answer.

So, 20/2 = 10, Therefore she gave 10 answers wrong.

Total questions answered by Neha = 10 + 10 = 20

Therefore,

Incorrect answers attempted by Neha = 10

Question:

(ii) Ajay also answered all the questions and scored (-12) marks though he got 4 correct

answers.

How many incorrect answers had he attempted?

Solution:

Correct answers = 4

Total marks scored = -12

If, marks scored for correct answers = 4×5 = 20

then 32 marks is lost for wrong answer.

So, 32/2 = 16, Therefore he gave 16 answers wrong.

Total questions answered by Neha = 4 + 16 = 20

Therefore,

Incorrect answers attempted by Ajay = 16