This is the 437th most frequent Serbian word.
лако
Easy.
The word "лако" is used here as an adverb to mean "easily" or "it's easy to." It expresses the ease of performing the action described in the sentence.
Лако је научити нешто ново када си заинтересован.
It's easy to learn something new when you're interested.
The word "лако" is used here as an adjective (describing the task) to state that the task was simple or not complex.
Тај задатак је био јако лако за решавање.
That task was very easy to solve.
In this context, "лако" functions as an adverb, indicating that the action of reaching someone by bus can be done without difficulty.