Translation of "usefulness" into Korean

But what is the use if the police department is in itself steeped in corruption?

하지만 경찰 자체가 부패에 깊이 빠져있다면 무슨 소용이 있겠습니까?

I took one class, but I've found that real-life experience is much more useful.

한 과목 듣긴 했는데, 실전 경험이 훨씬 더 유용한 것 같더라구요.