A: Can you help me with this problem? 
    - 이 문제 좀 도와줘?

B: What is it?
    - 뭔데?

A: I thought it would be easy.
    - 난 쉬울 거라고 생각했어.
    What do you think?
    - 어때?

B: Don't worry. It's a piece of cake!
    - 걱정마. 누워서 떡 먹기야.