SBI-Rate Concept Flashcards
Julie and Leo are partners on a science project. The ratio of the number of hours Julie spent on the project to the number of hours Leo spent on the project was 4:5. If Leo put in 25 hours on the project, how many hours did Julie spend on the project?
The automatic car wash can wash 3 cars in 6 minutes. What are the two quantities compared in this example? Is this a rate? How do you know? Find the unit rate.
Juanita drove her car 120 miles in 2 hours and Carlos drove 180 miles in 3 hours. Who drove faster, or did they drive the same average speed?
The population of Pittsburgh, Pennsylvania, is about 306,000 on its 56 square miles of land. The population of Norfolk, Virginia, is 246,000 on its 54 square miles of land. Find the unit rate of people per square mile for each city. Which city has greater population density (more people per mile)?
Stephanie is buying mozzarella cheese for a party she is hosting. She finds an 8 oz. package of Wisconsin mozzarella cheese for $2.99 and an 18 oz. package of imported mozzarella cheese for $9.99. Which package of cheese is the better value?
Rate: A special kind of ratio. It compares two quantities with different units and expresses a multiplicative relationship between the two quantities. (Examples: 4 pencils for $2.00; 300 miles in 5 hours; $3.07 for a 16-ounce box of cereal)
Unit rate: Expresses the relationship between one quantity and 1 unit of another quantity (e.g., 6 miles per gallon of gas, $6.50 earned in an hour, 8 chairs for each table, and 2 cans of water for every can of orange juice concentrate). It is a rate that has been simplified, so that the second term (denominator) is 1.
Equivalent rate: Two or more rates that have the same unit rate. (Example: 120 miles in 2 hours and 180 miles in 3 hours are equivalent rates because their unit rates are both 60 miles per hour.)
