Question

Prem appeared for five papers of an examination, where the full marks were the same for each paper. The ratio of the marks obtained by him in these papers are $5:6:7:8:9$ in all papers together , he obtained $60\%$ of the total marks. The number of papers in which he got more then $55\%$ of the marks is_____

• A. $1$
• B. $2$
• C. $3$
• D. $4$
• E. $5$

Answer 1

The correct option is C $3$

Here we can assume that one subject is of 100 marks so total there are 5 subjects$=100\times 5=500$

Now according to the question he secured 60% of those which 60% of 500$=\frac{60}{100}\times 500=300$ marks tn total

The ratio between the marks is given as $5:6:7:8:9$ , so now we can distribute 300 marks according to the ratio.

Total ratio$=5+6+7+8+9=35$

$For5:\left(\frac{300}{35}\right)\times 5=42.85$

$For6:\left(\frac{300}{35}\right)\times 6=51.42$

$For7:\left(\frac{300}{35}\right)\times 7=60$

$For8:\left(\frac{300}{35}\right)\times 8=68.57$

$For9:\left(\frac{300}{35}\right)\times 9=77.17$

Hence, there are 3 subjects where he secure more than 55%