Percentages are everywhere. You see them when you’re calculating a tip, figuring out a discount, or even just trying to understand statistics. A percentage is just a way of expressing a number as a fraction of 100, and they’re super useful for comparing ratios and understanding proportions.
So, let’s tackle a classic percentage problem: 15 is what percent of 25?
To solve this, we’ll use a simple formula to calculate the percentage. We’ll break down the solution step-by-step so you can easily find out what percentage 15 represents when compared to 25.
Breaking down the terms: part, whole, and percentage
When you’re trying to work out a percentage, it’s helpful to know the meaning of each term.
What’s the “part?”
The “part” is the smaller number you’re comparing to the larger number, or “whole.” In the problem “15 is what percent of 25,” the number 15 is the “part.”
In the real world, the number of students who show up for class on a given day is part of the whole class.
What’s the “whole?”
The “whole” is the total amount. It’s the base number you’re using for comparison. In the problem “15 is what percent of 25,” the number 25 is the “whole.”
The price of a sweater before the store adds a discount is the whole.
What’s a “percentage?”
A percentage is a number that’s expressed as a fraction of 100. It’s a way to show a ratio or proportion.
The symbol for percentage is “%.”
The percentage formula
The basic formula for figuring out percentages is:
Percentage = (Part / Whole) 100
This formula helps you find out what percentage of a number equals another number. The reason we multiply by 100 is to convert the decimal you get from the division into a percentage that we can easily read and understand.
So, in the question, “15 is what percent of 25,” 15 is the “part” and 25 is the “whole.” Therefore, you’d calculate the percentage like this:
Percentage = (15 / 25) 100
Another way to think about the formula is: Percent Whole = Part. This version can be helpful when you need to find the part, the whole, or the percent, and you already know the other values.
You can rearrange the formula like this:
- If you know the Percent and the Whole, then: Part = (Percent/100) Whole
- If you know the Part and the Percent, then: Whole = Part / (Percent/100)
How to solve “15 is what percent of 25”
Here’s a step-by-step guide to figure out what percentage 15 represents of 25:
- Restate the problem: “15 is what percent of 25?”
- Identify the parts: In this case, 15 is the “part” and 25 is the “whole.”
- Use the percentage formula: Percentage = (Part / Whole) 100
- Divide: 15 / 25 = 0.6
- Multiply by 100: 0.6 100 = 60
- State the answer: 15 is 60% of 25.
Think of it like a pie. If you cut a pie into 25 slices and you get 15 of those slices, you’re getting 60% of the pie.
Real-world applications of percentage calculations
Percentages aren’t just for math class. They’re used every day in all kinds of situations.
Discounts and sales
Stores often use percentages to show how much you’ll save on an item. For example, if an item that’s normally $50 is marked down by 20%, here’s how you’d figure out the discounted price:
- Discount amount = 20/100 $50 = $10
- Final price = $50 – $10 = $40
Tipping
When you eat at a restaurant, it’s customary to leave a tip. Here’s how you’d calculate a 15% tip on a $45 bill:
- Tip amount = 15/100 $45 = $6.75
- Total bill = $45 + $6.75 = $51.75
Test scores
Test scores are often expressed as percentages. If you score 80 out of 100 questions, here’s how you’d calculate your percentage:
- Percentage = (80 / 100) 100 = 80%
Financial calculations (interest rates)
Banks use percentages to calculate the interest they pay on savings accounts. For example, if you have $1000 in a savings account that pays 2% interest per year, you’d multiply $1000 by 0.02 to find out how much interest you’ll earn in a year.
In Summary
To find out what percent 15 is of 25, we used a simple formula: (Part / Whole) 100. In this case, that’s (15 / 25) 100, which equals 60%.
Understanding percentages is useful in lots of everyday situations. Whether you’re figuring out a tip, calculating a discount, or trying to understand statistics, knowing how to work with percentages can come in handy.
If you’d like to practice more percentage problems, you can find plenty of online calculators to check your work and sharpen your skills.