Question

in a mathematics test, there are 60 questions. there are 2 marks for every correct answer, and 1/3 is deducted for each unattempted question or wrong solution. if zaheer got 50 marks, how many questions did he answer correctly?

Answer 1

Answer:

30

Step-by-step explanation:

Let the number of questions answered correctly by Zaheer be x.

Then the number of questions answered incorrectly or left unanswered = 60-x.

• Zaheer scores 2 marks for every correct answer.

Therefore, marks scored from correct answers = 2×Number of questions answered correctly = 2x

• He loses 1/3 marks for each unattempted or incorrectly answered question.

Therefore total marks deducted from his score = 1/3×Number of questions left unattempted or answered incorrectly = 1/3(60-x)

• Zaheer's final score of 50 is arrived at when we subtract the deducted marks from the marks scored by answering correctly.

2x - 1/3(60 - x) = 50

2x - ((60/3) - (x/3)) = 50

2x - (20 - (x/3)) = 50

2x - 20 + x/3 = 50

2x + x/3 = 50 + 20

(6x + x)/3 = 70

7x/3 = 70

7x = 70 × 3

x = (70 × 3)/7

x = 30