This is the 17899th most frequent Polish word.
łatwością
"Ease" or "facility."
The word 'łatwością' is used here in the instrumental case of 'łatwość', indicating the manner in which the action is performed, emphasizing the ease of learning.
Uczy się nowych języków z łatwością.
He learns new languages with ease.
In this sentence, 'łatwością' is used in a comparative context to highlight the effortless manner in which the problem-solving occurred.
Rozwiązała to zadanie z taką łatwością, jakby robiła to codziennie.
She solved this problem with such ease as if she did it every day.
Here, 'łatwością' illustrates the unexpected or notable effortless ability of finding solutions by the subject.