Solve all the questions in context with the case study. Try minimizing external resources.

Case study Study the source material carefully and Open with question 1. Agriculture output in Africa The ouput of fertilizers and better irrigation have contributed to higher agricultural output for each unit of land in Africa in recent years. More significant, however, has been the Increase in the quantity of land used to grow crops. For example, in 1975, 12% of the land was used for agriculture. By 2015, this had increased to 25%. In Mauritania, agricultural expansion is particularly high at 7% per year. Despite the rise in agricultural output, the quantity of high quality food that the people would like to consume is not keeping pace with the rise In population in all African countries. Africa's population is set to double by 2050, which will increase even further the demand for food. As Incomes increase In Africa, the desire for a range of the products Is Increasing. People In Africa, for example, want more and better housing. Indeed, the desire for housing usually outstrips the growth in resources devoted to housing. People constantly strive for better living standards. The expansion of the house building industry is encouraging some farm workers to switch to working In the building industry. Changes in the pattern of demand are causing not only agricultural workers, but also other workers to change their occupation and where they work. Agricultural output can fluctuate quite significantly as it can be Influenced by, for example, floods, droughts and heatwaves. The contribution of the agricultural output varies between countries. For example, In 2015 agriculture accounted for only 2% of the South Africa's output, but 21% of Nigeria's output. The total output that a country produces is influenced by the size of the labour force. The table shows the size of the labour force and total output for a group of selected African countries. Country Labor force(millions) Total output(US$billion) Ethiopia 49 62 Ghana 12 38 Mali 6 13 Nigeria 58 481 South Africa 21 315 The Labour force and output of 5 African countries1. Referring to the source material in your responses, complete all parts of question 1 a) Identify two reasons why productivity of land has increased in South Africa? (3) b) Explain the opportunity cost of working on a farm? (3) c) Analyse, using a PPC, the effect on an economy of a flood? (4) d) Discuss whether or not skilled workers are likely to be more occupationally and geographically mobile than unskilled workers (6) e) Explain two examples of economic problem? (4)