Final answer:
To find out how much Fifi weighs, we need to subtract 720 grams from Pixie's weight and convert it to kilograms. Then, we subtract the converted weight from Pixie's weight to get Fifi's weight. Fifi weighs approximately 7.78 kilograms.
Step-by-step explanation:
To find out how much Fifi weighs, we need to subtract 720 grams from Pixie's weight. Since 1 kilogram is equal to 1000 grams, we need to convert 720 grams to kilograms by dividing it by 1000. So, 720 grams is equal to 0.72 kilograms. Now, we can subtract 0.72 kilograms from Pixie's weight of 8.5 kilograms to find Fifi's weight.
8.5 kg - 0.72 kg = 7.78 kg
Therefore, Fifi weighs approximately 7.78 kilograms.