Suppose function `k` gives the volume of water in a pool (in liters) in terms of the number of minutes, `t`, that have elapsed since you started filling that pool.

  1. `k` represents:


  2. Use function notation to represent the volume of water in the pool `23` minutes after you started filling it up.
     

  3. Use function notation to represent the volume of water in the pool `59` minutes after you started filling it up.