"这不是一个简单的问题。"

Translation: This is not a simple question.

[YoungjinSeoul]

I think 问题 doesn't necessarily mean literally a question. 'troubles' or 'problems' should be accepted as a correct answer.

[Kivolamuzikisto]

一个 makes this singular in English, so problem (no 's') should be accepted. And "a simple trouble" is just not a phase that's used in English.

[maartendoc]

简 (jiǎn) = simple/uncomplicated
单 (dān) = bill/list/form/single/only
简单 (jiǎndān) = simple

We saw 单 (dān) before in:

• 菜单 (càidān) = menu
• 买单 (mǎidān) = buying list (lit.) = the bill/check

[davidgriff623089]

Easy and simple should both be accepted

[Herbie21446]

I am still missing what makes it "not simple" instead of "simple"

[R7fi9dwS]

簡単 also means easy, I think.

[Ree413612]

That is just the traditional character of 简.

[yoshiihsoy]

In Japanese, yes.

[Firippu_FeiLi]

Is it necessary to use 一个 in this sentence?

[Rabea733910]

And is it necessary also to use 的 ?