If a radio is purchased for $Rs. 490$ and sold for $Rs. 465.50$,find the $\text{loss} \%$. (in $\%$)

Some articles were bought at $6$ articles for $Rs. 5$ and sold at $5$ articles for $Rs. 6$. The gain percent is: (in $\%$)

Aditya purchased a book with a $20 \%$ discount on the marked price. How much $Rs.$ did he pay if the marked price of the book was $Rs. 500$?

$A$ sells a suitcase to $B$ at $10\%$ profit. $B$ sells it to $C$ at $30\%$ profit. If $C$ pays $₹ 2,860$ for it,then the price at which $A$ bought it is (in $₹$):

$A$ man bought nine pens for a rupee. How many pens should he sell for a rupee to gain $50 \%$?

$A$ person incurs a $5 \%$ loss by selling a watch for $Rs. 1140$. At what price should the watch be sold to earn a $5 \%$ profit?