rates ratios and proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, expressed as 'a to b' or a:b.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve for a variable in a proportion?

Back

Cross-multiply the ratios and then solve for the variable.

Front

What is the unit price?

Back

The unit price is the cost per single unit of a product, used to compare prices.

Front

How do you find the percentage of a number?

Back

Multiply the number by the percentage (as a decimal). For example, 20% of 200 is 200 * 0.20 = 40.

Front

What is the formula for finding the total amount from a percentage?

Back

Total Amount = Part / (Percentage as a decimal). For example, if 40 is 20%, then Total Amount = 40 / 0.20 = 200.

Front

If 3 apples cost $1.50, what is the cost of 1 apple?

Back

Cost of 1 apple = Total cost / Number of apples = $1.50 / 3 = $0.50.

Front

What is the relationship between ratios and fractions?

Back

Ratios can be expressed as fractions, where the first quantity is the numerator and the second is the denominator.

Front

How do you convert a ratio to a percentage?

Back

Divide the part by the whole and multiply by 100. For example, if the ratio is 1:4, then (1/(1+4))*100 = 20%.

Front

What is a rate?

Back

A rate is a specific kind of ratio that compares two quantities with different units, such as speed (miles per hour).