How do I say "That's a piece of cake" in #Korean
I tend to use a lot of idioms and various colloquialisms in my general speech, could anyone let me know what Korean equivalent to the titled is?

Question

Answer

a piece of cake - 1. 식은 죽 먹기(eating a cold porridge)
                           2. 누워서 떡 먹기(lying and eating a rice cake)

I hope my explanaion will be helpful to you :)

Answer

"That's a piece of cake"
누워서 떡먹기

눕다 lie down
떡 rice cake
먹기 to eat