Because of using the formulae above, the thinking of solving problem was very clear and the difficulty of problem was reduced.

由于随用了“全概公式”及“逆概公式”而使解题的思路清晰，从而降低了题目的难度。

youdao

The difficulty of a problem was defined in terms of how long it took to complete.

问题的难易度是以解决这个问题所花时间的长短而定的。

《牛津词典》

Even without the problem of regional differences, rocks present a difficulty as unique time markers.

即使没有区域差异的问题，岩石作为独特的时间标记也是一个难题。

youdao

And the difficulty was basically the problem of duplication.

提出了一个难题，这难题就基于复制。

耶鲁公开课 - 死亡课程节选

In Healy's opinion, electronic gaming at a young age can lead to shorter attention spans, a lack of internal motivation, difficulty with problem solving and a lack of creativity.

FORBES: Baby Frankenstein

The lack of clarity reflects a fundamental problem in economics: the difficulty of isolating individual factors.

ECONOMIST: s struggle to answer a vital question

But as I listened, Doug, to the presentation, I don't think at least I have any difficulty with the diagnosis of the problem that threat facing us is international terrorism.

CENTERFORSECURITYPOLICY: Remarks to the Council on Foreign Relations