While selling $15$ items, a shopkeeper earned a profit equal to the total cost price of $3$ items. If each item is marked $25\%$ above its actual cost and a discount of $₹2$ is given while selling it, then what is the difference between the total cost price of $20$ items and the total selling price of $12$ items?

The sum of the cost prices of three items was $₹24,150$. The person sold the first item at a profit of $72\%$, the second item at a profit of $40\%$, and the third item at a profit of $126\%$. The total profit earned from the sale of these three items was $₹19,432$. If the cost price of the second item was $₹175$ more than what it actually was, then the ratio of the cost prices of the second and the third items, respectively, would have been $4 : 5$. What was the difference (in Rs.) between the profits earned from the sale of the first and the second items?

A shopkeeper sold article A at a profit of $18\%$ and article B at a loss of $10\%$, thus making an overall profit of Rs.$85$. If he had sold at article A at an $11\%$ loss and article B at an $8\%$ profit, he would have suffered a loss of Rs.$34$. Find the sum (in Rs.) of the cost prices of article A and article B.