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 $Rs.$
$80$
$75$
$90$
$100$
A single discount, equivalent to a successive discount of $40 \%$ and $30 \%$ is in $\%$?
A man buys $300$ dozen of bananas for $Rs.\, 3,600$. He sold $1 / 3^{rd}$ of the stock at a loss of $10 \%$ and the remaining $2 / 3^{rd}$ stock at a gain of $10 \% .$ Find his overall percent profit or loss.
A man bought $4$ dozen eggs at $Rs.\, 24$ per dozen and $2$ dozen eggs at $Rs.\, 32$ per dozen. To gain $20\%$ on the whole, he should sell the eggs at in $Rs.$ per dozen
cost price of $100$ books is equal to the selling price of $60$ books. The gain or loss percentage will be
Hundred oranges are bought at the rate of $Rs.\, 350$ and sold at the rate of $Rs.\, 48$ per dozen. The percentage of profit or loss is