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 questions would she have needed to answer correctly to earn a 60% passing grade?

Answer 1

Explanation:

problems solved in arithmetic=10×70 %=7

problems solved in algebra=30×40 %=12

problems solved in geometry=35×60 %=21

total problems solved=7+12+21=40

problems required for passing=75×60 %=45

so more questions required for passing=45-40=5

Answer 2

She would need 5 more correct answers.

Explanation:

This is from the AMC 8 1999 (the question). You can just search up the solution but okay.

70% of 10 is 7 so she got 7 arithmetic questions.

40% of 30 is 12 so she got 12 algebra questions.

60% of 35 is 21 so she got 21 geometry questions.

She got
`(7+12+21)/(10+30+35) =(40)/(75) =(8)/(15)` questions correct.

60% of 75 is 45 questions correct.

She got 40 questions correct.

She needed 5 more correct answers to get 60%.