On the other hand, what good does a vague answer do?

(哦,) 我是怎么信手拈来这么个数字的？ 不过话说回来，一个模糊的概念又有什么好处呢？

" Where they can not be done, they will clearly tell you "No" and are seldom put on airs, or gives a vague answer.

凡是他们办不到的，他们也会明确告诉你“不行”，很少摆架子，或者给人以模棱两可的答复。