$A$ sells an article to $B$ at a gain of $20 \%$,$B$ sells it to $C$ at a gain of $10 \%$,and $C$ sells it to $D$ at a gain of $12 \frac{1}{2} \%$. If $D$ pays $₹ 29.70$,then $A$ purchased the article for (in $₹$):

$A$ merchant advertises $10 \%$ off on the items bought from his store. The total discount obtained by a customer who bought a cooker worth $Rs. 650$,a heater worth $Rs. 500$,and a bag worth $Rs. 65$ is (in $Rs.$): (in $.50$)

Find $SP$ when $CP = Rs. 80.40$ and $\text{loss} = 5\%$.

$A$ wholesaler had $200$ dozens of mangoes. He sold some of these mangoes at $20 \%$ profit and the rest at $10 \%$ profit,so that he made $13 \%$ profit on selling all the mangoes. How many mangoes (in dozens) did he sell at $20 \%$ profit?

$A$ shopkeeper purchased $245$ pieces of an article at $Rs. 30$ per piece. He spent $Rs. 980$ on transport and $Rs. 1470$ on packing the articles. He sold the articles at the rate of $Rs. 50$ per piece. What is the percent profit earned?

$A$ trader mixes $26 \text{ kg}$ of rice at $Rs. 20$ per $\text{kg}$ with $30 \text{ kg}$ of rice of another variety at $Rs. 36$ per $\text{kg}$ and sells the mixture at $Rs. 30$ per $\text{kg}$. His profit percent is: