Since 1 task can be assigned to 1 person, we can start by assigning people to the task. There are 15 different task, so at the first task there are 8 choices, at the 2nd task there are also 8 choices, and so on. There's also the fact that these tasks are all different.
Therefore the total number of way to assign 8 people to 15 tasks is
The propeller-driven airplane has over the jet is that maximum thrust is ... efficiency at the higher altitudes is lost (turbofan engines are ... pilot is worse off than the propeller pilot. For ... applicable speed limit at all times.