Answer:
40%
Step-by-step explanation:
Finley's pumpkin had a mass of 6.5 kg before he carved it.
After carving it, the pumpkin had a mass of 3.9 kg.
Now, we are asked to determine the % decrease in the mass of the pumpkin.
Therefore, the % decrease in mass is given by
[tex]\frac{\textrm {Initial Mass - Final Mass}}{\textrm {Initial Mass}} \times 100= \frac{6.5 - 3.9}{6.5} \times 100 = 40[/tex]%. (Answer)