Question

In a competitive exam 4 marks are given for every correct answer and -2 marks for every wrong answer,Kalaivizhi attended the exam and answered all the questions and scored 20 marks only even though she got 10 correct answer.How many questions did she answer incorrectly?​

Answer 1

Answer:

10 questions were answered incorrectly.

Step-by-step explanation:

Let, total number of questions answered be X.

Given that, number of correct answer 10.

Then, number of incorrect answer (X-10).

So,

(10×4) + (-2) (X-10) = 20

or, 40-2X+20 = 20

or, 60-2X = 20

or, -2X = 20-60

or, -2X = -40

or, X = 20

Hence, number of incorrect answers

= (X-10)

= (20-10)

= 10

Answer 2

Answer:

10

Step-by-step explanation:

every correct answer - 4 marks

every incorrect answer - (-2) marks

kalivizhi scored - 20 marks

no of correct answers -10

no of incorrect answers -

for 10 correct answers she must have scored 40 marks in that case if she scored 20 marks we should subtract 40- 20 = 20 each incorrect answer 2 marks are reduced 20 ÷2 =10