An examination consists of 150 questions that are each worth one mark. Shabnam answered

[Mikrislac]

An examination consists of 150 questions that are each worth one mark. Shabnam answered 80% of the first 75 questions correctly. What percent of the remaining 75 questions does she need to answer correctly so as to obtain an overall score of 60%?

(A) 20

(B) 40

(C) 50

(D) 60

(E) 70

[Scott@TargetTestPrep]

An examination consists of 150 questions that are each worth one mark. Shabnam answered 80% of the first 75 questions correctly. What percent of the remaining 75 questions does she need to answer correctly so as to obtain an overall score of 60%?

(A) 20

(B) 40

(C) 50

(D) 60

(E) 70

Solution:

We can create the equation:

0.8 x 75 + n/100 x 75 = 0.6 x 150

60 + 3n/4 = 90

3n/4 = 30

3n = 120

n = 40

Answer: B