If Aditya sells an article to Nutan at $10 \%$ gain, while Nutan sells it to Manish at $20 \%$ gain at $Rs.\, 1914$ then what is the Cost Price in $Rs.$?

When Ram sold his book for $Rs.\, 255$ he made a loss of $15\%.$ For how much he should have sold it if he wanted to make a profit of $5 \% ?$

Two items $A$ and $B$ are sold at a profit of $10 \%$ and $15 \%,$ respectively. If the amount of profit received is the same, then the cost price of $A$ and $B$ may be (in $Rs.$)

A rice trader buys $8$ quintals of rice for $Rs.\, 3,600,10 \%$ rice is lost in transportation. At what rate should he sell to earn $15 \%$ profit in $Rs.$ per quintal ?

Sasha goes to a shop to buy a sofa set and a center table. Ske bargins for a $10 \%$ discount on the center table and and $25 \%$ discount on sofa set. However, the manager, by mistake, interchanged the discount percentage figures while making the bill and Sasha paid accordingly. When compared to what she should pay for her purchases, what percentage did Sasha pay extra given that the center table costs $40 \%$ as much as the sofa set.

The cost price of an article is $64 \%$ of the marked price. The gain percentage after allowing a discount of $12 \%$ on the marked price is........$\%$