Percents and Percent Proportions

Front

What is a percent?

Back

A percent is a ratio expressed as a fraction of 100. It represents a part of a whole.

Front

How do you calculate the percent of a number?

Back

To calculate the percent of a number, multiply the number by the percent (in decimal form) and then divide by 100.

Front

What is a percent proportion?

Back

A percent proportion is an equation that shows two ratios are equal, often used to find the percent of a quantity.

Front

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

Back

Divide the part by the whole and multiply by 100. Formula: (Part/Whole) x 100 = Percent.

Front

What is the formula for percent increase?

Back

Percent Increase = ((New Value - Original Value) / Original Value) x 100.

Front

What is the formula for percent decrease?

Back

Percent Decrease = ((Original Value - New Value) / Original Value) x 100.

Front

If 15 is what percent of 75, how do you solve it?

Back

Set up the equation: 15/x = 75/100. Cross-multiply and solve for x to find x = 20%.

Front

A student scored 80% on a test with 50 questions. How do you find the number of correct answers?

Back

Multiply the total questions by the percent: 50 x 0.80 = 40 correct answers.

Front

How do you calculate the percent decrease from $40 to $32?

Back

Percent Decrease = ((40 - 32) / 40) x 100 = 20%.

Front

If a car depreciates by 15% from $20,000, how do you find its new value?

Back

New Value = Original Value - (Original Value x Depreciation Rate). New Value = 20000 - (20000 x 0.15) = $17,000.