Fig. 1 shows information about Ahmad and his commercial activities. Ahmad grows large quantities of vegetables. He uses many of the vegetables to feed his family and he gives away some of them. He takes the surplus vegetables to a market once a week in his van and sells them to people in the local town. Before he comes home, he buys groceries in the self-service store and fish at the harbour. Sometimes he barters vegetables for fish. Fig. 1 Use the information given in Fig. 1 to help you to answer the following questions.