If the ratio of boys to girls is 3:2, then for every 3 boys, there are 2 girls. If there are 30 boys, we can set up the proportion: 3/2 = 30/x. Solving for x gives us x = 20. Therefore, there are 20 girls.

Let the score in the third subject be x. The average is (90 + 80 + x) / 3 = 85. Solving gives x = 90.

Total parts = 2 + 3 = 5. Y = (3/5) * 50 = 30 liters.

Total parts = 5 + 3 = 8. Volume of milk = (5/8) * 32 = 20 liters.

If milk is 5 parts, then water is 3 parts. Total parts = 5 + 3 = 8. Water = (3/5) * 40 = 24 liters.

Total parts = 5 + 3 = 8. Volume of milk = (5/8) * 64 = 40 liters.

Initial sugar = 1 part, water = 4 parts (8 liters). After adding 2 liters of sugar, new sugar = 2 liters, water = 8 liters. Ratio = 2:8 = 1:4.

Initially, there is 1 part sugar and 4 parts water, totaling 5 parts. In 20 liters, there are 4 liters of sugar and 16 liters of water. After adding 2 liters of sugar, the new ratio is 6:16, which simplifies to 1:5.

Initial sugar = 1 liter, water = 16 liters. After adding 2 liters of sugar, the new ratio is 3:16, which simplifies to 1:5.

Let the initial amount of sugar be x liters and water be 4x liters. After adding 2 liters of sugar, the new ratio becomes (x + 2) : 4x.

Initial sugar = 1 part, water = 4 parts. Total = 5 parts. New sugar = 2 liters, water = 8 liters. Ratio = 2:8 = 1:4.

Let the initial amounts be 2x and 3x. After adding 5 liters to the first component, the new ratio becomes (2x + 5):3x. Solving gives 3:2.

Let the number of cars be x. According to the ratio, 3/2 = 120/x. Cross-multiplying gives 3x = 240, so x = 80.

Let the number of cars be x. According to the ratio, 3/2 = 120/x. Cross-multiplying gives 3x = 240, so x = 80.

If the ratio of men to women is 3:2, then for every 3 men, there are 2 women. If there are 120 men, then the number of women can be calculated as follows: (2/3) * 120 = 80 women.

If the ratio of men to women is 3:2, then for every 3 men, there are 2 women. If there are 120 men, we can set up the proportion: 3/2 = 120/x. Solving for x gives x = 80. Therefore, there are 80 women.

If the ratio of men to women is 3:4, then for every 3 men, there are 4 women. If there are 120 men, we can set up the proportion: 3/4 = 120/x. Cross-multiplying gives us 3x = 480, so x = 160. Therefore, there are 160 women.

If the ratio of men to women is 3:4, then for every 3 men, there are 4 women. If there are 120 men, we can set up the proportion: 3/4 = 120/x. Solving for x gives x = 160. Therefore, there are 160 women.

Let the number of boys be x and the number of girls be 30 - x. The total score of boys is 80x and that of girls is 70(30 - x). The overall average is given by (80x + 70(30 - x)) / 30 = 75. Solving this gives x = 15.

Number of girls = 25% of 40 = 10. Number of boys = 40 - 10 = 30.

Number of girls = 40% of 50 = 20. Therefore, number of boys = 50 - 20 = 30.

Number of girls = 30% of 120 = 36. Therefore, number of boys = 120 - 36 = 84.

Let the total number of students be x. Then, 40% of x = 30. Therefore, x = 30 / 0.4 = 75.

If the ratio of boys to girls is 3:2, then for every 3 boys, there are 2 girls. If there are 30 boys, the number of girls can be calculated as (30 boys * 2 girls) / 3 boys = 20 girls.

The ratio of apples to oranges is 2:3. If there are 30 oranges, we can set up the proportion: 2/3 = x/30. Solving for x gives us x = 20. Therefore, there are 20 apples.

The ratio of apples to oranges is 7:5. If there are 35 apples, the number of oranges can be calculated as (35 apples * 5 oranges) / 7 apples = 25 oranges.

Total parts = 3 + 1 = 4. Volume of water = (1/4) * 40 = 10 liters.

Total parts = 4 + 1 = 5. Volume of the first chemical = (4/5) * 50 = 40 liters.

Total parts = 2 + 3 = 5. Alcohol's part = (3/5) * 60 = 36 liters.

Total parts = 7 + 3 = 10. Percentage of milk = (7/10) * 100 = 70%.