Ratios, rates, proportional relationships, and units：練習題

A car travels \( 150 \) miles on \( 5 \) gallons of gasoline. At this constant rate, how many gallons of gasoline will the car need to travel \( 450 \) miles?

A car travels at a constant speed of \( 60 \) miles per hour. How many feet does the car travel in \( 30 \) seconds? (Given that \( 1 \) mile = \( 5,280 \) feet)

Pipe A can fill an empty swimming pool in \( 6 \) hours, and Pipe B can fill the same empty pool in \( 12 \) hours. If both pipes are turned on at the same time, how many hours will it take to fill the pool?

A recipe for cookies calls for \( 3 \) cups of flour for every \( 2 \) cups of sugar. If a baker uses \( 9 \) cups of flour, how many cups of sugar should they use to maintain the same ratio?

On a map, a square region with an area of \( 4 \) square centimeters represents a real-world area of \( 100 \) square kilometers. If a rectangular forest has an area of \( 9 \) square centimeters on the same map, what is its actual area in square kilometers?

A landscape designer is using a scale where \( 2 \) inches on a blueprint represents \( 5 \) feet in the actual garden. If the length of a rectangular flower bed on the blueprint is \( 7 \) inches, what is the actual length, in feet, of the flower bed?

A car travels at a constant rate of 65 miles per hour. A second car starts at the same location 30 minutes later and travels at a constant rate of 75 miles per hour along the same route. How many hours after the first car starts will the second car catch up to the first car?