Question

There are 25 questions in the examination written by Jaffar. Each correct answer gets 2 marks. There is a Loss of mark of each wrong answer. Jaffar answered all the questions. He got 35 marks. Find out the number of correct answers.?​

Answer 1

Let :

• Number of correct answer = x
• Number of wrong answer = y

Given :

• Total number of questions = 25
• Marks scored by Jaffar = 35

To find : Number of correct answer

Solution :

Total number of answer = x + y

=> x + y = 25

=> x = 25 - y .......... equation 1

Marks scored by Jaffar = 2× Number of correct answer - 1×(Number of wrong answer)

35 = 2x - y

Putting value of x from equation 1, we get;

=> 35 = 2(25-y) - y

=> 35 = 50 - 2y - y

=> 35 = 50 - 3y

=> 3y = 50 - 35

=> 3y = 15

=> y = (15/3)

=> y = 5

putting value of y in equation 1 (x = 25-y)

=> x = 25 - 5

=> x = 20

ANSWER : Number of correct answer (x) = 20