5.1 Opener Ratios and Proportions Mini Lesson

Front

What is a ratio?

Back

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

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD).

Front

What is the ratio of violins to total instruments if there are 24 violins and 170 total instruments?

Back

The ratio is 24:170, which simplifies to 12:85.

Front

What is the ratio of trombones to trumpets if there are 16 trombones and 40 trumpets?

Back

The ratio is 16:40, which simplifies to 2:5.

Front

If 150 people wait 20 minutes for a ride, how long will 1,200 people wait?

Back

The waiting time for 1,200 people is 160 minutes.

Front

What is the ratio of flour to sugar if a recipe calls for 5 cups of flour and 15 cups of sugar?

Back

The ratio is 5:15, which simplifies to 1:3.

Front

Back

Cross-multiply to get 3(x-5) = 2(x+4), then solve for x to find x = 23.

Front

What is a proportion?

Back

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

Front

How can you check if two ratios form a proportion?

Back

Cross-multiply the ratios; if the products are equal, the ratios form a proportion.

Front

What is the simplest form of the ratio 24:36?

Back

The simplest form is 2:3.