Question

3 litre of bottle weighs around 2.6 kg when full. How much a 6 litre bottle will weigh when it is full?

Answer 1

3 litres of bottle when full weighs = 2.6 kg
1 litre of bottle when full weighs = $\frac{2.6}{3}$kg
6 litres bottle full weighs =$\frac{2.6}{3}\times 6=2.6\times 2=5.2\mathrm{kg}$