Question

A test has $175$ question. A candidate gets $4$ marks for each correct and loses $2$ mark for each wrong answer and loses $1$ mark for each unanswered question. A student scored $405$. On analysing his performance he concluded that he had not attempted $35$ question. How many question did he answer wrongly?

• A. $30$
• B. $25$
• C. $20$
• D. Cannot be determined

Answer 1

Answer: (C)

$20$

Let $x$ be the no. of questions he marked wrong.

no. of unattempted question $=35$

Total no. of questions $=175$

$\therefore$ no. of correct questions $=(175-35-x)$

Total marks he got $=405$

According to question

$(175-35-x)\times 4-x\times 2-1\times 35=405$

$\Rightarrow (140-x)4-2x=405+35$

$\Rightarrow 560-4x-2x=440$

$\Rightarrow 560-440=6x$

$\Rightarrow 6x=120$

$\Rightarrow x=20$

$\therefore$ no. of wrong answered marked questions $=x=20$