Final answer:
35% of Tia's plate is ham, after calculating that stuffing and mashed potatoes take up 65% of the plate combined.
Step-by-step explanation:
To determine what part of Tia's plate is ham, we need to calculate the portion of the plate occupied by stuffing and mashed potatoes and then subtract this from the whole plate. Tia's plate can be thought of as 1 whole or 100%. With 25% being stuffing and 2/5, which is equivalent to 40%, being mashed potatoes, we can add these two portions together (25% + 40% = 65%) to find the total portion of the plate that is not ham. Subtracting this from 100% gives us the portion that is ham: 100% - 65% = 35%. So, 35% of Tia's plate is ham.