Question

A student gets an aggregate of $60\%$ marks in five subjects in the ratio $10:9:8:7:6$. If the passing marks are $50\%$ of the maximum marks and each subjects has the same maximum marks, in how many subjects did he pass the exam?

• A. $2$
• B. $3$
• C. $4$
• D. $5$

Answer 1

Answer: (C)

$4$

Let the full marks of each subject is $100$.

So, total marks in five subjects $=500$
Student got $60\%$ aggregate marks i.e. $60\%$ of $50=300$ marks.
$10x+9x+8x+x+6x=300$
$\Rightarrow 40x=300$
$\Rightarrow x=\frac{300}{40}=7.5$
Marks in first subject $=10x=10\times 7.5=75$
Marks in second subject $=9x=9\times 7.5=67.5$
Marks in Third subject $=8x=8\times 7.5=60$
Marks in fourth subject $=7x=7\times 7.5=52.5$
Marks in last subject $=6\times 7.5=45$
Thus, he passed in $4$ subjects.