The price of $12$ chairs and $8$ tables is $Rs. 676$. What is the price of $21$ chairs and $14$ tables in $Rs.$?

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

Anil started a business with an investment of $Rs. 25,000$. After $3$ months,Vishal joined his business with a capital of $Rs. 30,000$. At the end of the year,they made a profit of $Rs. 19,000$. What will be Anil's share in the profit? (in $Rs.$)

$A$ man sold two watches for $Rs. 3750$ each. On one he gained $5 \%$,and on the other,he lost $5 \%$. What was his total gain or loss percentage?

$A$ person sells two articles,each for $Rs. 1040$. He incurs a $20\%$ loss on the first and a $10\%$ loss on the second. Find the overall percentage loss. (in $\%$)

$A$ tradesman gives $4 \%$ discount on the marked price and gives $1$ book free for buying every $15$ books and thus gains $35 \%$. The marked price is increased above the cost price by (approx.) (in $\%$).