Ratio of lemon to water to be mixed to prepare lemon juice is 3:5. For 12 lemons, the number of cups of water to be used is:
5 litres of water was mixed with 2 litres of lemon juice to make lemonade for a gathering. To make it tastier, if the quantity of lemon juice is tripled and that of water is doubled, find the new ratio between water and lemon juice.
Four student (a), (b), (c) and (d) measured the pH values of water, lemon juice and sodium bicarbonate solution. What is the correct decreasing order of pH values?