WAEC - Economics (2012 - No. 10)
A decrease in the demand for a product X resulted in a decrease in the demand for another product Y. The demand for X and Y is
derived
composite
joint
competitive
Explication
Joint demand is When two or more goods are jointly demanded to satisfy single need. Example demand for cars and petrol, pens and ink, tea and sugar, etc, computers and software. If the demand for car decreases, it will also affect the demand for petrol.