Answer:
Because of the amount of time Sam spent learning and relating all the job-training.
Step-by-step explanation:
There are many things that should be evaluated when hiring personnel for a company, the most important are the completed studies and the time of experience that they have for the position for which you plan to hire them.
In this case, Bill and Sam have the same studies completed, both are graduates of Computer Science.
But Sam has had work experience.
No work experience, but you do know the basis of your work since you had a decade of job-training.
That means that Sam does not have to learn everything new since he already brings knowledge about what to do.