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Question

Tori's mathematics test had 75 problems: 10 arithmetic, 30 algebra, and 35 geometry problems. Although she answered 70% of the arithmetic, 40% of the algebra, and 60% of the geometry problems correctly, she did not pass the test because she got less than 60% of the problems right. How many more problems would she have needed to answer correctly to earn a 60% passing grade?

Accepted Answer

First, calculate how many of each type of problem she got right: Arithmetic: 70% 10 = 0.70 10 = 7 Algebra: 40% 30 = 0.40 30 = 12 Geometry: 60% 35 = 0.60 35 = 21 Altogether, Tori answered 7 + 12 + 21 = 40 questions correct. To get a 60% on her test overall, she needed to get 60% 75 = 0.60 75 = 45 questions right. Therefore, she needed to answer 45 - 40 = 5 more questions to pass, so the correct answer is 5