7. A student completes a mathematics course and begins to work through past exam papers. He completes the first paper in 2 hours and the second in 1 hour 54 minutes.
Assuming that the times he takes to complete successive papers form a geometric sequence,
- find, to the nearest minute, how long he will take to complete the fifth paper,
- show that the total time he takes to complete the first eight papers is approximately 13 hours 28 minutes,
- find the least number of papers he must work through if he is to complete a paper in less than one hour.