What is the next number in this sequence: 8, 27, 64, 125 ?

Find the next 2 numbers in this sequence: 33, 46, 72, 111

The amount of water inside of a leaky boat is measured periodically after the boat has been in the water in different periods of time and are found to have a linear relationship. The results are given in the following chart:

Using the method of linear extrapolation based on the data from the table, how much water would you expect to be in the boat after minutes?