Question

A student took five papers in an examination where the full marks were the same for each papers this marks in these papers were in the proportion 6 : 7 : 8 : 9 : 10 In all the papers together the candidate obtained 60% of the total marks Then the number of papers in which he got more than 50% marks is

• A. 1
• B. 3
• C. 4
• D. 5

Answer 1

Answer: (C)

4

Let the marks obtained in 5 subjects be 6x, 7x, 8x, 9x and 10x Average score = 60%
$\therefore$ $\frac{6x+7x+8x+9x+10x}{5}=\frac{60}{100}\Rightarrow \frac{40x}{5}=\frac{60}{100}$
$\Rightarrow x=\frac{60\times 5}{100\times 40}=\frac{3}{40}=0.075$ $\therefore$ The marks are 0.45, 0.525, 0.6, 0.675 and 0.75,
i.e., $45\%,52.5\%,60\%,67.5\%$ and $75\%$
$\therefore$ Number of papers in which the marks exceed $50$ $\%$ $=4$