Does Razor fang stack with flinch chance of moves? Does Serene grace double the chance of Razor fang's flinch?

Question

If I'm using a Togekiss, and it uses Air Slash, with Serene Grace flinch chances are double (60% instead of 30%), but when adding a Razor Fang... do they both stack? And if true, which equation? Is it (30 x 2) + (10 x 2), or is it (30 x 2)+10? In one possibility is it doesn't stack, and it stays at 60%. But in another, it just adds 10 to the total, making a 70% chance of flinch. In the final one, the 10 from Razor Fang is doubled by Serene Grace, making it 20, and then added to the 60. (The same answer can be accomplished by adding 30+10 [From the Razor fang] and then doubling it). If it varies from Gen to Gen, tell me the different results for each gen. Thanks!

Comments

It stops stacking in Generation 5, but I don't know how they stack in Generation 4.

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No razor fang does not stack.
Source: https://pokemondb.net/ability/serene-grace

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That page is wrong.

Answer 1

Gen IV
Only certain moves are boosted, Air Slash included. So, 64%.

Gen V onwards
Serene Grace boosts Razor Fang and King's Rock. So, 68%.

https://m.bulbapedia.bulbagarden.net/wiki/Razor_Fang
https://m.bulbapedia.bulbagarden.net/wiki/Serene_Grace_(Ability)

Comments

The first part of the answer might be wrong, because the additional 10% chance mentioned by Bulbapedia might be an additional roll, instead of directly adding 10% to the first roll. The second roll is only effective if the first roll fails to cause flinching, so it's effective only 40% of the time. 10% times 40% is 4%, so razor fang might only add 4% to the flinch chance.
The second part of the answer is definitely wrong because the Pokemon DB page is outdated.

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Yeah I checked and you're right. Thanks.