Percent Increase or Decrease

Front

What is percent increase?

Back

Percent increase is the amount of increase expressed as a percentage of the original amount. It is calculated using the formula: \( \text{Percent Increase} = \frac{\text{New Value} - \text{Original Value}}{\text{Original Value}} \times 100 \% \.

Front

What is percent decrease?

Back

Percent decrease is the amount of decrease expressed as a percentage of the original amount. It is calculated using the formula: \( \text{Percent Decrease} = \frac{\text{Original Value} - \text{New Value}}{\text{Original Value}} \times 100 \% \.

Front

How do you calculate a 10% decrease on a number?

Back

To calculate a 10% decrease, multiply the number by 0.9. For example, for 100: \( 100 \times 0.9 = 90 \).

Front

How do you calculate a 15% increase on a number?

Back

To calculate a 15% increase, multiply the number by 1.15. For example, for 100: \( 100 \times 1.15 = 115 \).

Front

What is the formula for exponential growth?

Back

The formula for exponential growth is: \( y = a \cdot (1 + r)^t \), where \( a \) is the initial amount, \( r \) is the growth rate, and \( t \) is time.

Front

What is the formula for exponential decay?

Back

The formula for exponential decay is: \( y = a \cdot (1 - r)^t \), where \( a \) is the initial amount, \( r \) is the decay rate, and \( t \) is time.

Front

If a book costs $4.25 and has a markup of 30%, what is the selling price?

Back

The selling price is calculated as: \( 4.25 \times 1.30 = 5.53 \).

Front

What does it mean if a quantity is said to depreciate?

Back

Depreciate means to decrease in value over time, indicating a decay process.

Front

What is the difference between growth and decay in mathematical terms?

Back

Growth refers to an increase in value over time, while decay refers to a decrease in value over time.

Front

How do you express a 20% increase in a mathematical equation?

Back

A 20% increase can be expressed as: \( y = x \cdot 1.20 \), where \( x \) is the original value.