How WS's Upgrade Weapon calculation works ?

[emirusan07]

As we know Whitesmith's Upgrade Weapon skill gives us +10% success change for refining at job 70, detail here

But I'm curious how the Calculation works. Example, if we want to refine +5 to +6 lvl 3 weapon with the chance success is 60%, does the upgrade weapon effect work like

1. Hard +10%
so, 60% + 10% = 70&

or

2. Soft + 10%
= 60% + (10% from 60%)
= 60% + 6%
= 66%

Thx for advance