# Ratio Practice Questions

#### Question 1 refers to the following table:

##### Top Three Majors at Greenly Community College
 Percentage of Class in Major History Engineering Spanish Freshman 30 25 17 Sophomore 33 21 18 Junior 36 22 14 Senior 29 28 19

1. 14:36
2. 14:22
3. 7:11
4. 7:18
5. 14:18
1. 1/2
2. 1 1/2
3. 1 3/4
4. 2 1/4
5. 2 1/2
1. 15:23
2. 13:15
3. 10:15
4. 23:15
1. a. 18
2. b. 24
3. c. 30
4. d. 32
1. a. 2
2. b. 6
3. c. 8
4. d. 12
1. 12
2. 24
3. 32
4. 36
1. 1:πr2
2. 1:πr2/2π
3. 1:2πr/r2
4. 1:2πr1/2
5. 1:r/2
##### Question 8 is based on the following figure. 1. 3:5
2. 8:5
3. 8:11
4. 3:11
5. 8:6
1. 8:1
2. 12:1
3. 11:1
4. 7:1
1. 1
2. 9
3. 12
4. 20
##### 11. A solution contains 6% calcium. How many milliliters of solution can be made from 50 ml of calcium?
1. 833
2. 952
3. 1054
4. 2000

1. D: The percentage of juniors majoring in Spanish is 14. The percentage of juniors majoring in history is 36. The ratio 14:36 in lowest terms is 7:18.

2. B: Determine what the ratio of vinegar to the salad dressing as a whole is. Vinegar is 1/4 of a cup and the salad dressing as a whole is 1/4 cup vinegar plus 3/4 cup oil, or 1 cup. Thus, vinegar is 1/4 of the salad dressing. Therefore, 1/4 of 6 cups is 3/2 or 1 1/2 cups of vinegar.

3. D: First, calculate how many girls there will be after 10 more join the class: 13 + 10 = 23.

Then, express the number of girls compared to boys as a ratio: 23:15.

4. C: The ratio of left- to right-handed players will be proportional to the ratio 2:3. Therefore, 2/3=12/R , so that by cross-multiplying we get 2R = 36 or R = 18 right-handed players. The total number on the roster is therefore 12 + 18 = 30.

5. D: Set up and solve a proportion, as shown below, where is the number of drops of yellow food coloring. To solve the proportion, cross-multiply:
3/2=18/x
3x = 36
x = 12, Choice D.

6. D: A ratio of 3:2:1 gives a whole of 6 (in other words, in each set of 6 plants, there are 3 tomato, 2 broccoli, and 1 bell pepper plants). It takes 12 sets of 6 plants to total 72 plants. To determine how many tomatoes Hunter planted, multiply 3 by 12, for a total of 36, Choice D.

7. E. The area of the circle is πr2 while the circumference is 2πr. Taking the ratio of these two expressions and reducing gives: 2πr:πr2=1:r/2.

8. D: Since the figure represents the number line, the distance from point A to point B will be the difference  A, which is 5 – (-6) = 11. Likewise, the distance from point B to point C will be the difference  B, which is 8 – 5 = 3. So the ratio of the distances BC to AB will be 3:11.

9. C: To find the ratio, divide the number of midwives by the number of obstetricians. This yields 440,000/40,000 = 11. Therefore, the ratio is 11 to 1.

10. B: You are given the total number of students in the class and the fraction of students who are boys. With this information, you can determine the number of boys by multiplying 2/3 by 27. You will find that there are 18 boys in the class. You can then find the number of girls by subtracting the number of boys from the total number of students: 27 – 18 = 9.

11. A: Set up a ratio of 6/100=50/x , with equal to the total number of milliliters of solution. Then, solve by cross multiplying: 6= 5000, or x = 5000/6 = 833, Choice A.