There are 45 questions in an exam.for every correct answer 5 points and every wrong 3 points is deducted.if she got 185 point.how many correct answers did she get...

Answer 1

c = correct answes

w = wrong answe

She must answer 45 questions so the sum of right and wrong answers is 45.

c + w = 45

For every correct answer 5 marks is awarded and for every wrong answer 3 marks is deducted.

This means:

She got

c ∙ 5 - w ∙ 3 = 185 points.

Now you must solve system:

c + w = 45

5 c - 3 w = 185
____________

The solutions are:

c = 40

w = 5

40 correct answes

5 wrong answes

Checking the results.

c + w = 40 + 5 = 45

c ∙ 5 - w ∙ 3 = 40 ∙ 5 - 5 ∙ 3 = 200 - 15 = 185