Q1. The average age of boys in a class is 15 years and the average age of girls is 17 years. Average age of all the 30 students of the class is 16.2 years. If the difference between the no. of boys and girls is 6, find the number of boys in the class.
Ans - 12
Q2. Three containers of equal volume contain alcohol mixed with water. The ratio of alcohol and water are 2 : 5, 3 : 7 and 4 : 5 respectively. All these mixtures are poured into a large container. Find ratio of alcohol and water in the large container.
Ans - 649 : 1241
Q3. A sum of Rs 210 is to be divided among 40 students. If each boy gets Rs 4 and each girl gets Rs 6, find the no. of boys.
Ans - 15
Q4. In a class of 40 students, the average age of boys is 20 years and the average age of girls is 18 years. The fraction of girls out of the total students of the class is
Ans - Data insufficient
Q5. How many kg of sugar worth Rs 40/kg should be mixed with 15 kg of sugar worth Rs 32 / kg, such that by selling the mixture at Rs 42/kg, there may be a gain of 20%?
Ans - 9kg
Q6. A vessel is full of milk. 10 l of milk is taken out and replaced by water. This process is repeated once more. If at the end the ratio of milk and water is 9 : 7, find the initial amount of milk in the vessel.
Ans - 40L
Q7. In an alloy 15% is aluminium. To get 105 kg of aluminium, how much alloy will be required?
Ans - 700
Q8. The ratio of milk and water in a mixture is 3 : 2. How much part of the mixture should be replaced by water, so that the ratio of milk and water becomes 1 : 1?
Ans - 1/6
Q9. The ratio of alcohol and water in a vessel is 3 : 2.If 20 l of mixture is drawn from it and 20 l water is added, then the ratio becomes 9 : 11. Find the total quantity of the mixture initially.
Ans - 80L
Q10. A solution contains 15% diesel, 40% petrol and 45% kerosene. If 12.5% solution is replaced by kerosene and then 1/2 of the obtained solution is replaced by diesel, find the percentage of petrol in the mixture now.
Ans - 17.5
Q11. 30 kg of an alloy A is mixed with 50 kg of an alloy of B. If alloy A has copper and aluminium in the ratio 3 : 2 and alloy B has aluminium and tin in the ratio 1 : 4, find amount of aluminium in the new alloy.
Ans - 22kg
Q12. The ratio of milk and water in 63 l mixture is 4 : 3. If 14 l milk and 13 l water is added to solution, find the ratio of milk and water now
Ans - 5:4
Q13. Acid and water in two vessels A and B are in the ratio 2 : 3 and 2: 5 respectively. In what ratio, the liquid of both the vessels be mixed to obtain a new mixture in vessel C, having the ratio of acid and water 3: 5?
Ans - 25:7
Q14. Two containers contain mixture of milk and water in ratio 2 : 3 and 3 : 4. If both the containers are mixed in the ratio 1 : 1, then find the ratio of milk and water in the new container.
Ans - 29:41
Q15. A mixture containing 5 litres of water and certain quantity of milk worth ₹ 30 per litre. If pure milk worths ₹ 40 per litre, how much milk is there in the mixture ?
Ans - 15
