Question 1

1.1 In a certain area, 50% of the households are using electricity as a source of energy, 30% are using paraffin and 20% are using coal. The users of electricity use 25% for cooking, 25% for lighting, 20% for heating and 30% for small appliances. Coal is used only for cooking, and paraffin is used for cooking (50%), heating (25%) and lighting (25%).

1.1.1 Summarise all the possible energy usage outcomes using a tree diagram and write the probability values on the branches.(11)

1.1.2 What is the probability that a randomly chosen household will be using electricity for lighting?