I should have known the answer to his simple question.

我本应该知道他那个简单问题的答案的。

youdao

The question was so simple, and yet he couldn't answer it.

这么简单的问题他竟然没回答上来。

《新英汉大辞典》

But for all the pomp and theatre, it did not answer one simple question: who is now in charge of Russia?

但是相对于盛况空前的就职典礼，它却没有回答一个最简单的问题：现在谁掌管俄罗斯？

youdao

He says, oh it's a very simple question; it's not difficult to answer.

他答道,这问题太简单了,一点儿都不难回答

耶鲁公开课 - 古希腊历史简介课程节选

Meanwhile researchers around the world are trying to answer a simple question: Why did Iressa fail so dismally in the two big trials?

FORBES: Cover Story

Nine months ago, Pwned List was created to answer a simple question for users: Is your account among the millions whose credentials have been spilled onto the web?

FORBES: With 12 Million Hacked Users' Data, Pwned List Launches As A Breach Monitoring Service

This survey will try to answer a simple question.

ECONOMIST: Central Asia