In a class test 5 marks are given for every correct answer and (-2) marks for every incorrect answers. Riya answered all the questions and scored 30 marks though she got 10 correct answers. how many incorrect answers had she attempted?

Solution:

Total marks received by Riya = 30

Riya had given 10 correct answers.

So the marks Riya got for correct answers = 10 x 5 = 50 marks.(Since 5 marks are awarded for every correct ans.).

Since Riya sorced only 30 marks, so the marks she got for incorrect answers = 50 - 30 = 20.

Since (-2) is awarded for every incorrect answer, so the no. of question answered incorrectly by Riya

= 20 / 2 = 10.

Ans: 10.