c = correct answers
w = wrong answers
S = score
S = c ∙ 10 - w ∙ 1
S = 10 ∙ c - w = 10 ∙ 23 - 7 = 230 - 7 = 223
A test in Science is scored the following way: each correct answer earns 10 points
while each wrong answer earns one point less. In a 30-item test, Rafael got 23 correct
answers and 7 wrong answers. What was his score?
2 answers
don't use it to a venm diagram, it's just a problem solving.