Question : The purity of a metal can be determined with the help of

Option 1: Pascal's law

Option 2: Boyle's law

Option 3: Archimedes Principle

Option 4: Conservation of mass principle

Question : Which of the following liquids has the least density?

Option 1: Freshwater

Option 2: Saltwater

Option 3: Petrol

Option 4: Mercury

Question : A canister holds 36 litres of a mixture of milk and water in a ratio of 3 : 1. 15 litres of milk is added to the canister. The new ratio of the mixture is:

Option 1: 12 : 5

Option 2: 14 : 3

Option 3: 7 : 4

Option 4: 9 : 4

Question : If 60 litres of a milk solution has 40% milk in it, then how much milk should be added to make the milk 60% in the solution?

Option 1: 30 litres

Option 2: 25 litres

Option 3: 20 litres

Option 4: 35 litres

Question : A milkman mixes water with milk and sells the mixture at the cost price of pure milk. The volume of water in litres to be mixed with each litre of milk to get a 25% profit is:

Option 1: $\frac{1}{4}$ litre

Option 2: $\frac{1}{5}$ litre

Option 3: $1\frac{1}{4}$ litre

Option 4: Cannot be calculated without knowing the cost price of milk.