Ratios, Rates, and Proportions Flashcards
6 cards from real Rise Placement Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Ratios, Rates, and Proportions flashcards as text
A recipe for a fruit smoothie requires 2 cups of strawberries for every 3 cups of yogurt. If you want to make a larger batch using 12 cups of yogurt, how many cups of strawberries will you need?
Answer: 8 cups
The ratio of strawberries to yogurt is 2:3. To find out how many cups of strawberries are needed for 12 cups of yogurt, you can set up a proportion: 2/3 = x/12. To solve for x, you can cross-multiply (2 * 12 = 3 * x), which gives 24 = 3x. Dividing both sides by 3 gives x = 8. Therefore, 8 cups of strawberries are needed.
A car travels 240 miles on 8 gallons of gasoline. What is the car's unit rate of fuel consumption in miles per gallon (MPG)?
Answer: 30 MPG
To find the unit rate, divide the total distance traveled by the total amount of gasoline used. Rate = Distance / Volume. So, 240 miles / 8 gallons = 30 miles per gallon (MPG).
A map has a scale of 1 inch : 25 miles. If the distance between two cities on the map is 4.5 inches, what is the actual distance between the cities?
Answer: 112.5 miles
This is a proportion problem. The scale is 1 inch / 25 miles. Set up the proportion: 1/25 = 4.5/x. Cross-multiply to solve for x: 1 * x = 25 * 4.5. This simplifies to x = 112.5. The actual distance is 112.5 miles.
Which of the following ratios is NOT proportional to 15/20?
Answer: 10/15
First, simplify the given ratio 15/20 by dividing both the numerator and the denominator by their greatest common divisor, which is 5. This gives 3/4. Now, check which of the answer choices is not equivalent to 3/4. A) 3/4 is equivalent. B) 30/40 simplifies to 3/4 (divide by 10). C) 9/12 simplifies to 3/4 (divide by 3). D) 10/15 simplifies to 2/3 (divide by 5), which is not equivalent to 3/4.
A quality control inspector found 6 defective items in a batch of 400. At this rate, how many defective items would be expected in a batch of 1,800?
Answer: 27
Set up a proportion comparing defective items to the batch size. The ratio is 6 defectives / 400 items. Let 'x' be the number of defective items in the new batch. The proportion is 6/400 = x/1800. Cross-multiply: 6 * 1800 = 400 * x. This gives 10800 = 400x. Divide by 400 to find x: x = 27. So, 27 defective items are expected.
A store sells a 12-ounce bottle of shampoo for $4.80 and a 20-ounce bottle of the same shampoo for $7.00. Which statement correctly identifies the better buy?
Answer: The 20-ounce bottle is the better buy because its unit price is $0.35 per ounce.
To determine the better buy, calculate the unit price (cost per ounce) for each bottle. For the 12-ounce bottle: $4.80 / 12 ounces = $0.40 per ounce. For the 20-ounce bottle: $7.00 / 20 ounces = $0.35 per ounce. The 20-ounce bottle has a lower unit price, making it the better buy.