Lack of interest with 知ったことか
Grammar: Unsorted » 知ったことか
The expression 知ったことか implies a lack of interest in a thing.
“I have nothing to do with it.”
Examples
Don't care if it troubles you with 知ったことか

Oyaji presented Colors with a bomb to defuse via a riddle, which led to problems for Saitou. After Colors successfully defuses the bomb, Saitou tells Oyaji to stop playing bothersome games.
- おやじ:
- 「子供のためだ。お前が迷惑被ろうと知ったことか」
- “It's for the kids. I don't care if it will cause you trouble.”
Nothing to do with Ayumu's situation with 知ったことか

Sakurako tells Takeru not to go to the shogi club as he’ll get in the way of Ayumu being with Urushi. However, as a new member of shogi club, and as a man, Takeru feels it’s his duty to show up.
- タケル:
- 「歩の事情など知ったことか」
- “This has nothing to do with Ayumu's situation.”