In 2017 1.54 billion smartphones were sold. The average smartphone weighs 150g and has a composition corresponding to that of electronic waste listed in the table below. Please answer the following questions with a link or reference to your source of information:\ a. How much gold is required to produce smartphones in 2017? (please show your work) \ b. Where (what country) is most of the gold mined in the world? (Need to include a reference- website or other for b, c, d) \ c. Where are most of the smartphones manufactured? \ d. What happens to most smartphones at the end of their lives?