# Percentages

**Percentages**

Percentages are an essential concept in quantitative aptitude and mathematics, widely used in various real-life scenarios and problem-solving situations. It represents a part of a whole, where the whole is considered 100%.

Here are some key aspects of percentages in quantitative ability:

**Percentage Calculation:**

To calculate it, we have to divide the part by the whole and then multiply the result by 100.

Example: What is 20% of 150?

Solution: 20% of 150 = (20/100) * 150 = 0.2 * 150 = 30.

**Finding a Percentage Increase or Decrease:**

To find the percentage increase or decrease, use the formula: Percentage Change = (Change / Original Value) * 100.

Example: If the price of a product increases from $50 to $60, what is the percentage increase?

Solution: Percentage Increase = ((60 - 50) / 50) * 100 = (10 / 50) * 100 = 20%.

**Percentage as a Fraction or Decimal:**

A percentage can be expressed as a fraction or decimal by dividing the percentage value by 100.

Example: Convert 25% to a decimal.

Solution: 25% as a decimal = 25 / 100 = 0.25.

**Finding the Original Value:**

To find the original value when the percentage change and the new value are known, use the formula: Original Value = (New Value / (1 + Percentage Change)).

Example: If the final price of a product is $90 after a 10% discount, what was the original price?

Solution: Original Price = (90 / (1 - 0.10)) = 90 / 0.90 = $100.

**Percentage Problems in Real-Life Scenarios:**

Percentage concepts are frequently used in various real-life scenarios, such as calculating discounts, calculating taxes, analysing profit or loss percentages, determining interest rates, and interpreting statistical data.

Understanding percentages is crucial for making informed decisions in finance, business, and daily life. It is also a fundamental skill in quantitative aptitude tests, competitive exams, and problem-solving challenges. Being comfortable with percentages allows individuals to interpret and compare data effectively, making it an important skill for both students and professionals alike.