Aspringer spaniel weighs 20 kilograms 490grams. a cocker spaniel weighs 7,590 grams less than a springer spaniel. a newfoundland weighs 52 kilograms 656 grams more than a cocker spaniel. what is the difference, in grams, between the weights of the newfoundland and the springer spaniel?

It is important that the units of measurement for the masses will be expressed in one unit only. For the purpose of illustration in this problem, we express the masses in kilograms. Hence, the mass of Springer Spaniel is equal to 20.49 kg. With this concept, we determine the mass of Cocker Spaniel.

Mass of Cocker Spaniel = 20.49 kg - 7.59 kg = 12.9 kg 

From this calculated mass, we determine the mass of the Newfoundland,
 
Mass of Newfoundland = 12.9 kg + 52.656 kg = 65.556 kg

The difference of the weights of Newfoundland and Springer Spaniel,
   D = 65.556 kg - 20.49 kg = 45.066 kg

ANSWER: 45.066 kg