Understanding Ratios and Rates

What is a ratio used for?

• Comparing quantities of different kinds.

• Comparing quantities with different units.

• Comparing quantities of the same kind that are measured in the same unit.

• Comparing quantities of the same kind that are measured in different units.

What are equivalent ratios?

• Ratios that compare different quantities.

• Ratios that are the same when we compare them.

• Ratios that have different units.

• Ratios that are always simplified.

Which ratio is equivalent to 27 : 45?

• 9 : 15

• 5 : 3

• 2 : 3

• 1 : 2

What is the simplest form of the ratio 800 g : 1.8 kg?

• 4 : 9

• 8 : 18

• 80 : 180

• 1 : 2.25

What is a rate?

• A ratio that compares quantities of the same unit.

• A special ratio that compares two quantities with different units of measurement.

• A simplified ratio.

• A ratio that always involves time.

What are the two quantities involved in the rate of a car consuming 1 litre of petrol for a distance of 12 km?

• Distance and time

• Mass and volume

• Distance and volume

• Speed and distance

A metal has a density of 2700 kg per cubic meter. What is its density in grams per cubic centimeter?

• 27 g/cm³

• 2.7 g/cm³

• 0.27 g/cm³

• 270 g/cm³

If 10 beans have a mass of 17 grams, and 30 beans have a mass of 51 grams, which proportion correctly represents this situation?

• 10 beans / 51 g = 30 beans / 17 g

• 17 g / 10 beans = 51 g / 30 beans

• 10 beans / 17 g = 51 g / 30 beans

• 17 g / 51 g = 30 beans / 10 beans

The cost of electricity for 2 kWh is 43.6 sen. What is the cost of electricity for 30 kWh?

• 65.4 sen

• 654 sen

• 218 sen

• 21.8 sen

In a class, the ratio of storybooks to reference books is 2:5. The ratio of reference books to magazines is 3:2. What is the ratio of storybooks to reference books to magazines?

• 2:5:2

• 6:15:10

• 5:3:2

• 10:15:6