Question

Ram got $20$% marks more than Girish. Girish get $20$% more than Sanjay. Sanjay gets $20$% less than Aditya. If Ram gets $576$ marks and total marks were $800$ then what marks did Aditya get:

• A. $600$
• B. $480$
• C. $500$
• D. $580$

Answer 1

The correct option is C $500$

Let marks obtained by Aditya be $x$ and denote marks obtained by Sanjay, Girish, and Ram by $M_s,M_g$ and $M_r.$

Marks obtained by Sanjay is $20\%$ less than Aditya so,

$M_s=(1-\frac{20}{100})x$

$=\left(\frac{80}{100}\right)x$

$=0.8x$

Marks obtained by Girish is $20\%$ more than Sanjay so,

$M_g=(1+\frac{20}{100})M_s$

$=\left(\frac{120}{100}\right)0.8x$

$=1.2\times 0.8x$

$=0.96x$

Marks obtained by Ram is $20\%$ more than Girish so,

$M_r=(1+\frac{20}{100})M_g$

$=\left(\frac{120}{100}\right)0.96x$

$=1.2\times 0.96x$

$=1.152x$

It is given that marks obtained by Ram are equal to $576,$

$\begin{array}{cc}1.152x& =576\\ x& =\frac{576}{1.152}\\ & =500\end{array}$

Hence, marks obtained by Aditya are equal to $500.$