Where and when pants were invented, or first commonly worn? Did multiple cultures invent pants independently, or should they be most associated with a particular region of the world?
Do you mind clarifying what you mean by pants?
The oldest known pair of trousers are roughly 3,300 year old pair found in Xinjiang region, China. Due to the cut they confirm academics current theories that they were developed as riding tousers for the nomadic people that wore them. Otzi the Ice man who was found clothed and dates to around 5,300 years of age has a pair of leggings much more comparable to hose, that are individual legs and tie to a lion cloth (or similar on the top).
Sorry i cannot answer your entire question but I hope this helps.