5. Self-Test

Answers to the questions are available at the end of the book.

1. Which is cheaper: a 240-gram box of cereal for $3.69, or a 360-gram box of cereal for $4.89?
2. A 500 km trip by car took 6 hours and 45 minutes. Calculate the average speed of the car in km/h.
3. The average speed of a car is 75 km/h. At this speed, how many hours will it take to travel 700 km?

For problems 4 and 5, solve the proportion equations for the unknown value.

4. 1. [latex]35 : 7 = 60 : x[/latex]
   2. [latex]45 : x = 70 : 63[/latex]

5. 1. [latex]25 : 9 = x : 2.7[/latex]
   2. [latex]\displaystyle{x : 8 = 2\frac{1}{4} : 2\frac{1}{2}}[/latex]

6. The scale on a map is 3 cm = 50 km. Calculate the actual distance between two cities that are 12.75 cm apart on the map.
7. An investment of $1,500 earned $820 in interest in one year. What amount should be invested at this rate to earn $1,459 in interest?
8. A car travelled 250 km. If the car’s fuel efficiency is 9 litres per 100 km, calculate the amount of gas used for the trip.
9. Which offer is the best based on the unit price?
   1. 75 grams of chocolate for $1.49
   2. 100 grams of chocolate for $1.99
   3. 125 grams of chocolate for $2.25
10. Andrew’s earnings to Bill’s was in the ratio of 3 : 5 and Bill’s to Cathy’s was in the ratio of 4 : 6. What was the ratio of the earnings of Andrew : Bill : Cathy?