Question

in a test +3 marks are given for every correct answer and -1 for every incorrect answer Mary attempted all questions and scored +20 marks though she got 10 correct answers (1)how many incorrect answers has she attempted? (2)how many questions were given in the test?

Answer 1

10

20

Explanation:

correct c=3 x 10

incorrect i=-1

-------

• 3c-i=20
• 3*10-i=20
• i=10

incorrect= 10

number of questions= 10+10= 20