The ratio of red to blue balls is 3:5. If there are 40 blue balls, we can set up the proportion: 3/5 = x/40. Solving for x gives us x = 24. Therefore, there are 24 red balls.

The ratio of red to blue balls is 5:3. If there are 40 red balls, the number of blue balls can be calculated as (3/5) * 40 = 24 blue balls.

The total parts of the ratio 3:2 = 5. The distance covered at the first speed is (3/5) * 150 km = 90 km.

The speed of the car is 60 km/h and the speed of the bike is 40 km/h. The ratio of their speeds is 60:40, which simplifies to 3:2.

In the ratio of 3:2, the total parts = 3 + 2 = 5. The amount of milk is (3/5) * 50 liters = 30 liters.

The ratio of flour to sugar is 4:1. If you have 8 cups of flour, the amount of sugar needed is (8 cups flour * 1 sugar) / 4 flour = 2 cups of sugar.

The ratio of sugar to flour is 1:4. If you have 200 grams of flour, then the amount of sugar needed is (1/4) * 200 = 50 grams.

Let A's age be 5x and B's age be 3x. Then, 5x + 3x = 64, which gives 8x = 64. Therefore, x = 8, and A's age is 5x = 40 years.

Let the lengths of the sides be 7x and 5x. Then, 7x + 5x = 48, which gives 12x = 48. Thus, x = 4, and the longer side is 7x = 28 cm.

The ratio of cats to dogs is 2:3. If there are 30 dogs, the number of cats can be calculated as (2/3) * 30 = 20 cats.

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.

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.

If the ratio of teachers to students is 1:20, then for 1000 students, the number of teachers is 1000 / 20 = 50 teachers.

If the shorter side is 16 cm and the ratio is 4:5, then the longer side can be calculated as (5/4) * 16 cm = 20 cm.

The ratio of cats to dogs is 4:3. If there are 28 cats, we can set up the proportion: 4/3 = 28/x. Solving for x gives us x = 21. Therefore, there are 21 dogs.