a piece of cake
US /ə piːs əv keɪk/
UK /ə piːs əv keɪk/

1.
식은 죽 먹기, 아주 쉬운 일
something that is very easy to do
:
•
The exam was a piece of cake; I finished it in half the time.
시험은 식은 죽 먹기였어. 절반의 시간 만에 끝냈지.
•
Learning to ride a bike was a piece of cake for him.
자전거 타는 법을 배우는 것은 그에게 식은 죽 먹기였다.