If the cost price of 20 articles equals the selling price of 16 articles, what is the profit or loss percentage?
A profit of 25%. Let each article cost ₹1. Then 16 articles sell for ₹20, so one sells for ₹1.25, a profit of 25%. Formula: (20 - 16)/16 x 100 = 25%.
Explain it simply
The money from selling 16 items is enough to buy 20 items. So selling brings in more than buying costs, which means profit. The 4 extra items are the profit, and they are earned while selling 16 items, so you divide by 16, the number actually sold.
Example
Question: CP of 20 articles = SP of 16 articles. Find the profit or loss %.
- Let CP of one article = ₹1. CP of 20 = ₹20.
- SP of 16 = ₹20, so SP of one = 20/16 = ₹1.25.
- Profit per article = ₹0.25 on ₹1 = 25% profit.
General rule: if CP of x articles = SP of y articles, profit % = (x - y) / y x 100. If y is larger than x the result is negative, meaning a loss.
Example of a loss: CP of 15 = SP of 20 gives (15 - 20) / 20 x 100 = -25%, a 25% loss.
const pct = (x, y) => ((x - y) / y) * 100;
console.log(pct(20, 16)); // Output: 25
console.log(pct(15, 20)); // Output: -25What to say in the interview
"I set the cost of one item to 1 rupee. Twenty rupees comes in from selling 16, so each sells for 1.25, a 25% profit. In general it's x minus y over y, with y the number sold."
Common mistakes
- Dividing by 20 and answering 20%.
- Getting the direction wrong: if the count sold is smaller, it is a profit.