1) At what percent above the cost price must a shopkeeper mark his goods so that he gains 20% even after giving a discount of 10% on the marked price ? A) 25% B) 30% C) $33\frac{1}{3}$% D) $37\frac{1}{2}$% E) 40% Answer: Option CExplanation:Let C.P = Rs. 100. Then S.P = Rs. 120. Let marked price be Rs. $x$. Then, 90% of $x=120$ $\Rightarrow$ $x$ $=\left(\frac{120 \times 100}{90}\right)$ $\therefore$ Marked price $=33\frac{1}{3}$% above C.P
