To find the amount of water in Tank A after 27.5 minutes, we can substitute \( t = 27.5 \) into the expression for Tank A, which is given as:
\[ \text{Liters in Tank A after t minutes} = 400 + (-3t) \]
Substituting \( t = 27.5 \):
\[ \text{Liters in Tank A} = 400 + (-3 \cdot 27.5) \]
Now, calculate \( -3 \cdot 27.5 \):
\[ -3 \cdot 27.5 = -82.5 \]
Now, substitute this value back into the expression:
\[ \text{Liters in Tank A} = 400 - 82.5 \]
Now, perform the subtraction:
\[ 400 - 82.5 = 317.5 \]
Therefore, the amount of water in Tank A after 27.5 minutes is 317.5 liters.