Condition duration and damage reduction

Question:suppose of having:

runes: antitoxin (-24% condition duration)food:sweet bean bun (-20% condition duration)

so its -44% condition duration or something different?

condition damage:traits as adaptive armor (engineer with scrapper trait)gain toughness (5 stacks) when struck and -20% condition damage

in this kind of setting (antitoxin-24% + food-20%)1000damage and 10s of poison each stack

becomes 800 damage (for the adaptive armor) and 5.6s (-44% conditon duration) of poison each stack,

is this correct?

The mitigation to condition duration will stack. The damage you receive is a different issue because it depends on other factors, like how many stacks of a condition are on you.