Question

In an examination, $+5$ marks are scored by a student if a question is answered correctly and $-2$ marks are scored by a student if a question is answered incorrectly. If Markus attempts $x$ questions correctly and $y$ questions incorrectly, find the total marks scored by Markus in the examination.

• A. $5x+2y$
• B. $5x\times 2y$
• C. $-5x+2y$
• D. $5x-2y$

Answer 1

The correct option is D $5x-2y$

According to the question,

Marks scored for one correct answer $=+5$
$\therefore$ Marks scored for $x$ correct answer(s)
$=x\times$ Score for one correct answer
$=x\times 5$
$=5x$

$\because$ Marks scored for one incorrect answer $=-2$
$\therefore$ Marks scored for $y$ incorrect answer(s)
$=y\times$ Score for one incorrect answer
$=y\times (-2)$
$=-2y$

Total marks scored by Markus would be obtained by adding the marks scored for correct answers to the marks marks scored for incorrect answers.

$\therefore$ Total marks scored by Markus $=5x+(-2y)$
$=5x-2y$

Here, 5x and -2y are unlike terms and that's why the algebraic expression cannot be further simplified.

As a result, total marks scored by Markus would be $5x-2y$.

Therefore, option (d.) is the correct answer.