There are 45 questions in an exam. For every correct answer 5 marks awarded and for every wrong answer 3 marks are deducted. Melissa scored 185 marks. How many correct answers did she give?

Answer 1

c = correct answers

w = wrong answers

Since there are 45 questions on the exam, it means that the sum of correct and wrong answers is 45.

c + w = 45

5 marks awarded for every correct answers , 3 marks are deducted for every wrong answers answers and Melissa scored 185 marks means:

5 c - 3 w = 185

Now you must solve system:

c + w = 45

5 c - 3 w = 185
____________

Try to solve this.

The solutions are:

c = 40 , w = 5

40 correct answers and 5 wrong answers.

Check results:

40 ∙ 5 - 5 ∙ 3 = 200 - 15 = 185