Goods that are normally consumed together are known as 'Complimentary Goods' i.e. they compliment one another.
Other examples include toothbrush and toothpaste or Car and Gasoline.
Car and Gasoline is a classic example of complementary goods since the increase or decrease in the demand for one product has a direct impact on the other.
For example, when Gasoline prices start to decline, there is generally an upward trend in the purchase of new cars and vice versa.
