Following graphs, which show the relationship of the water use and population in country X and how water use is distributed among various sections.

In 1970 if 5% of the water used was for domestic purposes, approximately what was the daily average number of litres of water used per capita for domestic purposes?

Villagers living close to a giant aluminum refinery complain that the refinery built next to their land is destroying their crops. However, the company spokesman of the refinery says that the refinery is not to be blamed and their research shows that the damage is due to insects and fungi Which of the following if true most seriously weakens the conclusion drawn by the company spokesman ?