SAT Practice Math Questions: Ratios
After you know the tricks, ratios are some of the easiest problems to answer quickly on the SAT Math test. Here are the points to remember:
- A ratio is written as
The ratio of sunflowers to roses =
The ratio of umbrellas to heads = umbrellas : heads.
- A possible total is a multiple of the sum of the numbers in the ratio.
You may have to confront a proportion problem like this on the test:
At a party, the ratio of blondes to redheads is 4:5. What could be the total number of blondes and redheads at the party?
This one’s easy. Just add the numbers in the ratio: 4 + 5 = 9. The total must be a multiple of 9, such as 9, 18, 27, 36, and so on.
Now try some examples.
- While creating his special dish, Thomas uses 7 teaspoons of whipped topping for every 5 teaspoons of chocolate mousse. Which of the following could be the total number of teaspoons of whipped topping and chocolate mousse in his special dish?
- A. 75
- B. 57
- C. 48
- D. 35
- To congratulate his team, which had just won the last game for an undefeated 21-in-0 season, the ecstatic coach took his team to the local pizza joint, where each player ordered either a deep dish pizza or a calzone. If there were 3 deep dishes for every 4 calzones, and if every member of the 28-man squad ordered either one or the other, how many deep dishes were there?
Answers and explanations
- C. Add the numbers in the ratio: 7 + 5 = 12. The total must be a multiple of 12. (It must be evenly divisible by 12.) Here, only 48, Choice (C), is evenly divisible by 12. Of course, 75 and 57 try to trick you by using the numbers 7 and 5 from the ratio.
- 12. Here’s how to solve it:
Now you have all the information you need to answer a variety of questions: How many deep dish pizzas were there? 12. How many calzones were there? 16. How many more calzones than deep dish pizzas were there? 4. How many additional calzones would have to be eaten for the number of calzones and deep dish pizzas to be equal? 4. The SAT-writers can ask all sorts of things, but if you have this information, you’re ready for anything they throw at you.