1.In a mixture of milk and water of the volume of 60 litre the ratio of milk to water is 7:5. How much quantity of water will be added to make mixture of equal ratio?

2.In a mixture of milk and water of the volume of 30 Litre, the ratio of milk and water is 8:7. How much water should be added in mixture to make ratio 4:5?

3. In what ratio must oil at Rs. 62 per kg be mixed with oil of Rs. 72 per kg, so that the mixture must be worth Rs. 64.50 per Kg?

4. A mixture of milk and water measures 60 ltr. It add contains 20% water. How many litres of water should be added to it so that water may be 25%?

5. In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.5 per kg?

6. A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 20%. The percentage of water in the mixture is?

7. Find the ratio in which rice at Rs. 7.20 a kg be mixed with rice at Rs. 5.70 a kg to produce a mixture worth Rs. 6.30 a kg?

8.Aditya and Sanjay started a business investing 45000 and 30000 respectively. What will be the ratio between their profit?

9.In what ratio must sugar at Rs. 2 per kg be mixed with sugar at Rs. 3.50 per kg so that the mixture be worth Rs.2.50 per kg?

10.600 gm of Sugar solution has 40% sugar in it. How much sugar should be added to make it 50% in the solution?

11. A motorist covered the first 20 km of his journey in 30 minutes and the remaining 29 km in 40 minutes. His average speed in km/hr is:

12.The average of nine numbers is 50. The average of the first five numbers is 54 and that of the last three numbers is 52. Then, the sixth number is?

13. The mean of 19 observations is 4. If one more observation of 24 is added to the data, the new mean will be:

14. A student bought 4 books for Rs. 120 from one book shop and 6 books for Rs. 150 from another. The average price (in rupees), he paid per book was:

15. The average of the price per kg. of rice at 10 different places was Rs. 4.85. After a week, the price per kg. was increased by 20 paise at 3 places and decreased by 10 paise at one place. The new average of price per kg is:

16. The average weight of a group of 20 boys was calculated to be 89.4 kg and it was later discovered that one weight was misread as 78 kg instead of the correct one of 87 kg. The correct average weight is:

17.A class has 20 boys and 30 girls. The average age of boys is 11 years and that of girls is 12 years. What is the average age of the whole class

18. Find the average of the following set of scores 253, 124, 255, 534, 836, 375, 101, 443, 760

19. What will be the average of even numbers between 11 to 63?

20.Find average of all prime numbers between 60 and 90.