Texas Hold'em Jackpot

A Texas Hold'em game is offering jackpot that is won on Royal Flush. RF on Flop pays 100%, on Turn 20%, and on River 10%. The "catch" is that the player has to use their own two cards to form a RF.
The question is, what are the odds of hitting RF on Turn and on River, if the player has to use their original two cards.
It would be greatly appreciated if somebody could share how these two values can be calculated.

Didn't you already ask about this here? https://wizardofvegas.com/forum/questions-and-answers/advice/41520-texas-holdem-jackpot/#post961644

At River, it’s C(52,5)/C(5,3)=649740/10=64,974, so 1 in 64,974.
At Turn, it’s C(52,5)/C(4,3)=649740/4=162,435, so 1 in 162,435.