A tank starts with 300 liters of water. It is being drained at a rate of 3 liters of water per minute. The variable t represents the time in minutes.

Question

Write an expression to represent the amount of water in the tank after t minutes.
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How many liters of water will be in the tank after 20 minutes? You can substitute 20 minutes for t in the expression to solve.
Liters in the tank after t minutes:

300+(−3t)
After 20 minutes, there will be
liters of water in the tank.
You got it!
How many liters of water will be in the tank after 5 minutes? You can substitute 5 minutes for t in the expression to solve.
Liters in the tank after t minutes:

300+(−3t)
After 5 minutes, there will be ? liters of water in the tank.

Answer 1

The expression for the amount of water in the tank after \( t \) minutes is:

\[ 300 - 3t \]

To find the amount of water in the tank after 20 minutes, substitute \( t = 20 \):

\[ 300 - 3(20) = 300 - 60 = 240 \]

So, after 20 minutes, there will be 240 liters of water in the tank.

Now, for 5 minutes, substitute \( t = 5 \):

\[ 300 - 3(5) = 300 - 15 = 285 \]

Therefore, after 5 minutes, there will be 285 liters of water in the tank.