What is the formula to calculate the percentage increase or decrease?

To calculate the percentage increase or decrease, use the formula: ((new value - original value) / original value) × 100. For example, if a price increases from $50 to $70, the percentage increase is ((70 - 50) / 50) × 100 = 40%.

How do you find what percentage one number is of another?

To find what percentage one number (part) is of another number (whole), use the formula: (part / whole) × 100. For example, to find what percentage 30 is of 150: (30 / 150) × 100 = 20%.

A store sells a laptop for $800 after applying a discount of 20%. What was the original price?

To find the original price, let the original price be x. The equation is x - (20/100)x = 800. Simplifying gives (80/100)x = 800, so x = 800 × (100/80) = $1000. The original price was $1000.

If 80% of a number is 240, what is the number?

Let the number be x. The equation is (80/100)x = 240. Solving gives x = 240 × (100/80) = 300. Therefore, the number is 300.

What is the effect of a 10% increase followed by a 10% decrease on a number?

Let's say the original number is x. After a 10% increase, it becomes x × 1.1. Following a 10% decrease: (x × 1.1) × 0.9 = x × 0.99. Thus, the final result is 99% of the original number, showing a net decrease of 1%.

What does it mean when a quantity is said to be 150% of another?

When a quantity is 150% of another, it means it is 1.5 times that quantity. For example, if the original amount is 200, then 150% of 200 is 1.5 × 200 = 300.

If an item costs $40 and it is marked up by 15%, what is the new price?

To calculate the new price after a 15% markup: New price = original price + (15/100) × original price = 40 + (15/100) × 40 = 40 + 6 = $46. The new price is $46.

If a student scores 75% on a test with 60 questions, how many questions did the student answer correctly?

To find the number of correct answers, calculate: (75/100) × 60 = 45. Therefore, the student answered 45 questions correctly.

A population of a town increases from 5000 to 5500. What is the percentage increase in population?

To find the percentage increase: ((5500 - 5000) / 5000) × 100 = (500 / 5000) × 100 = 10%. The percentage increase in population is 10%.

If you have a budget of $200 and you spend 30% of it, how much do you have left?

First, calculate 30% of $200: (30/100) × 200 = $60. Then subtract this from your budget: 200 - 60 = $140. You have $140 left.