A white goods dealer pays $10 \%$ custom duty on an i-phone that costs $Rs.\, 25000$ in $UK$. For how much should hemark it, if he desires to make a profit of $20 \%$ after giving a discount of $25 \%$ to the buyer? (in $Rs$)

Seema sells a pen to Sapna at a profit of $25 \% .$ Sapna sells it to Asha at a profit of $10 \%$ and Asha sells it to Kavita at a profit of $5 \%$. If Asha sells it for $Rs.\,231,$ find the cost price at which Seema bought the pen? (in $Rs.$)

A sold a horse to $B$ for $Rs.\, 4800$ by losing $20 \%$. $B$ sells it to $C$ at a price which would have given $A$ a profit of $15 \% .$ $B's$ gain is (in $Rs.$)

A man purchased $150$ pens at the rate of $Rs.\, 12$ per pen. He sold 50 pens at gain of $10 \% .$ The percentage gain at which he must sell the remaining pens so as to gain $15 \%$ on the whole outlay is........$\%$

A man buys two chairs for a total cost of $900.$ By selling one for $\frac{4}{5}$ of its cost and the other for $\frac{5}{4}$ of its cost, he makes a profit of $90$ on the whole transaction. The cost of the lower priced chair is (in $Rs.$)

A dealer fixed the price of an article $40 \%$ above the cost of production. While selling it he allows a discount of $20 \%$ and makes a profit of $Rs.\, 48$. The cost of production (in $Rs.$) of the article is