Question

Tank A starts with 400 liters of water. It springs a leak and is losing 3 liters of water per minute. At the same time, Tank B starts with 180 liters of water and is being filled at a rate of 5 liters per minute.
Let’s write an expression to represent the number of liters left in Tank A after t minutes, where t represents the number of minutes. We’ll go step by step. How much water starts in Tank A?
Tank A
starts with 400 liters
leaking 3 liters per minute


+ ?
Tank B
starts with 180 liters
filling 5 liters per minute

Answer 1

To determine the amount of water left in Tank A after \( t \) minutes, we need to account for the initial amount of water in Tank A and the rate at which it is losing water.

1. **Initial amount of water in Tank A**: 400 liters
2. **Rate at which Tank A is losing water**: 3 liters per minute

After \( t \) minutes, the amount of water lost from Tank A will be \( 3t \) liters. Therefore, the expression for the amount of water left in Tank A after \( t \) minutes can be formulated as follows:

\[
\text{Water left in Tank A} = \text{Initial amount} - \text{Water lost}
\]

This gives us:

\[
\text{Water left in Tank A} = 400 - 3t
\]

So the expression for the number of liters left in Tank A after \( t \) minutes is:

\[
400 - 3t
\]