One-banana problem字面上看是“一个香蕉的问题”，真实含义指很容易的事，易如反掌的事或问题。

【例句】
I can figure it out. It's just a one-banana problem.
我能解决这个问题，它是易如反掌的事。

Don't worry. It's a one-banana problem.
别担心。小菜一碟。