In a test of 50 questions, each correct answer fetches two marks and each wrong answer fetches -(1/2) marks. A candidate attempted all the questions and scored 40 mark. How many questions did he attempt correctly?

Question

In a test of 50 questions, each correct answer fetches two marks and each wrong answer fetches -(1/2) marks. A candidate attempted all the questions and scored 40 mark. How many questions did he attempt correctly? (A) 24 (B) 26 (C) 22 (D) 20

Tardigrade Admin · Accepted Answer

Let the number of questions which are correct be c and the questions which are wrong be w. c+w=50 (1) 2 c-(w/2)=40 4 c-w=80 (2) From Eqs. (1) and (2), we have ⇒ 5 c=130 ⇒ c=26

Q. In a test of 50 questions, each correct answer fetches two marks and each wrong answer fetches $- \frac{1}{2}$ marks. A candidate attempted all the questions and scored 40 mark. How many questions did he attempt correctly?

24

26

22

20

Let the number of questions which are correct be $c$ and the questions which are wrong be $w$ .
$c + w = 50$ (1)
$2 c - \frac{w}{2} = 40$
$4 c - w = 80$ (2)
From Eqs. (1) and (2), we have $\Rightarrow 5 c = 130 \Rightarrow c = 26$

Q. In a test of 50 questions, each correct answer fetches two marks and each wrong answer fetches −21​ marks. A candidate attempted all the questions and scored 40 mark. How many questions did he attempt correctly?

24

26

22

20

Let the number of questions which are correct be c and the questions which are wrong be w. c+w=50 (1) 2c−2w​=40 4c−w=80 (2) From Eqs. (1) and (2), we have ⇒5c=130⇒c=26

Q. In a test of 50 questions, each correct answer fetches two marks and each wrong answer fetches $- \frac{1}{2}$ marks. A candidate attempted all the questions and scored 40 mark. How many questions did he attempt correctly?

Let the number of questions which are correct be $c$ and the questions which are wrong be $w$ .
$c + w = 50$ (1)
$2 c - \frac{w}{2} = 40$
$4 c - w = 80$ (2)
From Eqs. (1) and (2), we have $\Rightarrow 5 c = 130 \Rightarrow c = 26$