The marked price of a bed is $Rs. 2400$ .The shopkeeper gives successive discounts of $10 \%$ and $X \%$ to customer. If the customer pays $Rs.\, 1836$ for's the bed then find the value of $X$ in $\%$?

The list price of an article at a showroom is $Rs.\, 2000$ and it is being sold at successive discounts of $20 \%$ and $10 \% .$ Its net selling price will be (in $Rs.$)

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 $Rs.$)

On selling $17$ balls at $Rs.\, 720$, there is a loss equal to the cost price of 5 balls. The cost price of a ball is (in $Rs.$)

Ram sold two horses at the same price. In one he gets a profit of $10 \%$ and in the other he gets a loss of $10 \% .$ Then Ram gets

Ravipurchases $90$ pens and sells $40$ pens at a gain of $10 \%$ and $50$ pens at a gain of $20 \% .$ Had he sold all of them at a uniform profit of $15 \%$ he would have got $Rs.\, 40$ less. Find the cost price of each pen in $Rs.$