The value of an article depreciates every year at the rate of $10 \%$ of its value. If the present value of the article is $Rs. 729$,then its worth $3$ years ago was (in $Rs.$)

$A$ sells a bicycle to $B$ at a profit of $20 \%.$ $B$ sells it to $C$ at a profit of $25 \%.$ If $C$ pays $Rs. 225$ for it,the cost price of the bicycle for $A$ is (in $Rs.$)

$A$ man buys $10$ articles for $Rs. 8$ and sells them at $Rs. 1.25$ per article. His gain percent is

$APD$ printed $3000$ copies of 'Career Power' at a cost of $Rs. 240000$. It gave $500$ copies free to different philanthropic institutions. It allowed a discount of $25\%$ on the published price and gave one copy free for every $25$ copies bought at a time. It was able to sell all the copies in this manner. If the published price is $Rs. 325$,then what is its overall gain or loss percentage in the whole transaction?

$A$ loss of $19 \%$ gets converted into a profit of $17 \%$ when the selling price is increased by $Rs. 162$. The cost price of the article is (in $Rs.$)

$A$ cab driver makes a profit of $20 \%$ on every trip when he carries $3$ passengers and the price of petrol is $Rs. 30$ a litre. Find the percentage profit for the same journey if he goes with four passengers per trip and the price of petrol reduces to $Rs. 24$ a litre? (in $\%$)
(Assume that revenue per passenger is the same in both the cases.)