Topic Details (Notes format)

How to Calculate the Percentage of a Number?

Subject: Mathematics

Book: Maths Mastery

Percentages are central to countless real-world applications—from calculating exam marks to determining discounts and interest rates. The general formula to find a percentage is: (Part / Whole) × 100%. However, if you already know the rate and the whole, use Percentage of a Number = (Rate ÷ 100) × Whole. For example, to calculate 20% of 150, convert 20% to 0.20, then multiply: 0.20 × 150 = 30. This concept is pivotal in areas like finance and data analysis, so practice by computing percentages for tips in restaurants, taxes on shopping bills, or proportionate contributions in group projects. Mastering this skill builds a strong foundation for advanced percentage operations such as percentage increase, decrease, and compound interest calculations.

Practice Questions

If x^3 - 3x^2 + 4 = 0, what is one root of the equation?

View Question

What is the square root of 121?

View Question

If x:y = 4:5 and y:z = 2:3, what is x:z?

View Question

If the probability of an event is 1/4, what is the probability of its complement?

View Question

What is the area of a circle with a diameter of 14 cm?

View Question

A train 150 m long passes a pole in 15 seconds. What is its speed?

View Question

What is the length of the diagonal of a square with a side length of 7 cm?

View Question

What is the greatest common divisor (GCD) of 36 and 48?

View Question

If sin(A) = 3/5 and cos(B) = 5/13, where A and B are acute angles, what is sin(A+B)?

View Question

If sin(θ) = 0.6 and θ is acute, what is cos(θ)?

View Question