The water tank initially contains 76 liters, and it is being drained at a constant rate of 2.5 liters per minute.

After 2 minutes, the amount of water drained is:

$2.5 \times 2 = 5 \, \text{liters}$

Now, subtract the drained water from the initial amount:

$76 - 5 = 71 \, \text{liters}$

So, after 2 minutes, there are approximately 71 liters of water left in the tank.

Would you like more details or have any questions?

Here are some related questions to consider:

1. How much water will be left after 10 minutes?
2. How long will it take to empty the tank completely?
3. If the drainage rate changes to 3 liters per minute, how much water will remain after 2 minutes?
4. What is the formula for calculating the water left after any number of minutes?
5. If water is added at a rate of 1 liter per minute while draining, how much water will be left after 5 minutes?

Tip: For problems involving constant rates, linear equations are a great tool!