易い and 簡単 what is the difference?
If this words are synonims, which way to use their?

Question

易い and 簡単 what is the difference? 
If this words are synonims, which way to use their?

Answer

"易しい(yasashii)" and "簡単(kantan)" have almost same meaning "easy".
ex) 易しい問題、簡単な問題　easy question
But "簡単" also means "simple" , while "易しい" doesn't have such meaning.
ex) 簡単に説明する。explain simply. (may be in a few words) .
     易しく説明する。explain (may be in detail) in order to be easy to understand.