WAEC - Economics (2009 - No. 11)
The type of demand that exist between torchlight and battery is
competitive demand
complemetary demand
composite demand
joint demand
توضیح
Joint demand occurs when the demand for one product is directly linked to the demand for another. This means the two goods need to work together to provide a benefit for the consumer and one cannot work without the other. E.g car and petrol, torch and batteries.