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 $Rs.$
$80$
$75$
$90$
$100$
Ajit caculates his profit percentage on the selling price whereas Rohit calculates his on the cost price. They find that the difference of their profits is $Rs.\, 100.$ If the selling price of both of them are the same and both of them get $25\%$ profit, find their selling price? (in $Rs.$)
A shopkeeper labeled the price of his articles in order to earn a profit of $30 \%$ on the cost price. He, then, sold the articles by offering a discount of $10 \%$ on the labelled price. What is the actual rate of profit he earned in the deal? (in $\%$)
Arun purchased $30\, kg$ of wheat at the rate of $Rs.\,11.50$ per $kg$ and $20\, kg$ of wheat at the rate of $Rs.\,14.25$ per $kg$. He mixed the two and sold the mixture. Approximately at what price per $kg$ should he sell the mixture to make $30 \%$ profit? (in $Rs.$)
A shopkeeper has to sell $24\, Kg$ of sugar. He sells a part of these at a gain of $20 \%$ and the rest at a loss of $5 \% .$ If on the whole he earns a profit of $10 \%$, the amount of Sugar sold at a loss is in $Rs.$?
A person earns $15 \%$ on investment but loses $10 \%$ on another investment. If the ratio of the two investments be $3: 5,$ what is the gain or loss on the two investments taken together in $\%$?