Question

In a class test (+4) marks are given for every correct answer and (-2) marks are given for every incorrect answer and no marks for not attempting any questions. Amana answered all the questions and scored 30 though she got 10 correct answers. i) Number of questions she has attempted incorrectly is. ii) Number of questions given in the test

Answer 1

Given :-

• Total marks given for each correct answer = 4
• Total marks deducted for each incorrect answer = 2
• Total marks scored by Amana = 30
• Number of correct answers given by her = 10

To Find :-

1. Number of questions she has attempted incorrectly.
2. Number of questions given in the test.

Solution :-

Suppose x be the number of incorrect answers given by Amana. Then, total marks reduced will be : -2(x)

Also, she had given 10 correct answers. Then, total marks she got (before been reduced) = 4 × 10 = 40

According to the question,

⇒ 40 - 2x = 30

⇒ 2x = 40 - 30

⇒ 2x = 10

⇒ x = 10/2

⇒ x = 5

Therefore, Amana attempted 5 questions incorrectly.

Also,

Total number of questions in the test,

⇒ 10 + 5 ( ∵ she attempted all questions).

⇒ 15

Hence,

1. Number of questions she had attempted incorrectly = 5
2. Number of questions given in the test = 15