A 5lb bag of flour is about $2.75. There are about 18 cups of flour in a five pound bag. Divide the cost 2.75 by the number of cups (18) and the answer is about 15 cents per cup.

Depends what the substance is. - 15 cups of flour is about 4 pounds. 15 cups of water is about 7.5 pounds. 15 cups of fine table salt could be 9 pounds -

In 2.5 cups of flour, there is 5.925 dl. This measurement assumes that your flour has been sifted and has not settled into a denser mass through prolonged storage.