Question

Anjali wrote a 30-item multiple choice exam and answered every question. She got 8 points for each correct item. She lost 2 points for each incorrect item. Her total score was 150 points. How many items did she answer correctly?​

Answer 1

She did 21 question correctly.

Correct Answer :

Let number of correct answers : x

Let number of wrong answer : y

Given, Total question wrote : 30

So,  

      x + y = 30          (i) - equation

Got 8 point on each correct answer, total point : 8*x

Got -2 point on each wrong answer, total point : (-2)*y

Total point she score was : 150          (given)

so, our next equation is

                                      8*x - 2*y = 150       (ii) - equation

                                      y = 30 - x            [from (i) - equation]

put in (ii) - equation, we get

                                    8*x - 2*(30 - x) = 150

                                    8*x - 60 + 2*x = 150

                                    10*x = 210

                                       x = 21

Therefor, only 21 answers are correct.

To learn more about how find the total score or marks, refer :

https://brainly.com/question/462774

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