To find the total amount of money Quentin will have paid after 3 hours of labor, we can use the function \( c(t) = 40 + 25t \).
Substituting \( t = 3 \) into the function:
\[ c(3) = 40 + 25(3) \]
Calculating the labor cost:
\[ c(3) = 40 + 75 \]
Now, adding these amounts together:
\[ c(3) = 115 \]
Therefore, the total amount of money Quentin will have paid after 3 hours of labor is $115.