Discussion Forum

In an examination in which full marks were 500, A got 10% less than B, B 25% more than C and C 20% less than D. If A got 360 marks. Marks obtained by D is? 

Answer:

Explanation:

Let the mark obtained by $D = x$

Mark obtained by $C = x-0.2x$ $= 0.8x$

Marks obtained by $B = 0.8\times (1+0.25)x$

$= (1.25\times 0.8)x$

$=x$

Marks obtained by $A = x-0.1x$ $=0.9x$    

Given $0.9x = 360$

 $x = \frac{360}{0.9}$ $= \frac{3600}{9}$ $= 400$

% of mark obtained by $D = \left(\frac{400}{500}\right)\times 100 = 80$%