Final answer:
The manager used the utilitarian view of ethics, which focuses on maximizing overall happiness or welfare, by retaining 90 percent of the workforce and keeping the company solvent.
Step-by-step explanation:
The manager who decided to lay off 10 percent of the workforce to keep the company solvent has utilized the utilitarian view of ethics. This ethical view is concerned with the consequences of an action, judging it to be moral if it maximizes overall happiness or general welfare. In this case, the manager believes that by laying off a smaller portion of the workforce, the greater number of employees (90 percent) can continue to have jobs, and the company can remain operational.