Two discounts of $40 \%$ and $20 \%$ equal to a single discount of $\%$?

A trader mixes $26\, kg$ of rice at $Rs$. $20$ per $kg$ with $30\, kg$ of rice of other variety at $Rs.\, 36$ per $kg$ and sells the mixture at $Rs.\, 30$ per $kg.$ His profit percent is

A dealer fixed the price of an article $40 \%$ above the cost of production. While selling it he allows a discount of $20 \%$ and makes a profit of $Rs.\, 48$. The cost of production (in $Rs.$) of the article is

$APD$ printed $3000$ copies of 'Career Power' at a cost of $Rs.$ $240000 .$ It gave $500$ copies free to different philanthropic institutions. It allowed a discount of $25 \%$ on the published price and gave one copy free for every $25$ copies bought at a time. It was able to sell all the copies in this manner. If the published price is $Rs.$ $325,$ then what is its overall gain or loss percentage in the whole transaction?

Instead of dividing $391$ cookies among $3$ children $A$, $B,C$ in the ratio $\frac{1}{5}: \frac{1}{4}: \frac{1}{8},$ it was divided in to the ratio $5: 4: 8 .$ Who gains the most and how many?

By selling an article at $\frac{2}{5}$ of the marked price, there is a loss of $25 \%$. The ratio of the marked price and the cost price of the article is