“No Problem”，可以在回答，没问题，不客气是来用。

No problem is quite an informal way of saying ‘you’re welcome’. 

It could also mean ‘yes, I can do it’, and is seen as a way of saying ‘This is easy, I can do it, and it doesn’t pose any problems’. Another way this could be said is, in response to

Another way this could be said is, in response to expression of regret, or gratitude when no thanks, or apology is necessary.

Example 1:

“Could you help me with this please?”
“Sure, no problem”
Example 2:
“Thank you for helping yesterday”
“It was no problem at all”
I have listed some more below, and labelled them ‘I’ or ‘F’ to signify formal and informal expressions.

No Problem 的同义词：
Sure thing (I)
No worries (I)
Cool (I)
It’s all gravy (I)
It’s all right (I)
You’re welcome (F)
Certainly (F)
Of course (F)
That’s OK (I)
No at all (F)
That’s absolutely fine (F)
Don’t mention it (F/I)
It’s nothing (I/F)
No probs (I)
You’re very welcome (F/I)
It’s my pleasure (F)
No sweat (I)

Now try to use a different one each day, so you get to practise different ways of saying ‘no problem’, every time!!