Ratio, Proportion, Percent

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

What is a proportion?

Back

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

Front

How do you calculate a percentage?

Back

To calculate a percentage, divide the part by the whole and then multiply by 100.

Front

What is the formula for percent change?

Back

Percent Change = ((New Value - Old Value) / Old Value) x 100.

Front

How do you find the tip amount based on a percentage?

Back

Tip Amount = Total Bill x (Tip Percentage / 100).

Front

What is simple interest?

Back

Simple interest is calculated using the formula: Interest = Principal x Rate x Time.

Front

What does a 900% markup mean?

Back

A 900% markup means the selling price is 9 times the cost price added to the original cost.

Front

How do you determine if two ratios form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

Front

What is the total cost if an item costs $28 and has a 900% markup?

Back

Total Cost = Cost + (Cost x Markup Percentage) = $28 + ($28 x 9) = $280.

Front

If a student has 27 students last year and 30 this year, what is the percent change?

Back

Percent Change = ((30 - 27) / 27) x 100 = 11%.