Легко

Russians teenagers (and not only teenagers. Me too :D ) have begun to use "легко" instead of "да".

- Сходи за хлебом.
- Легко.

- Давай встретимся завтра.
- Легко.

And yesterday I watched a TV interview where a reporter asked an adult if they could eliminate a breakdown in a week and he answered "легко". :D

I heard this word even in mid 80-s, so it's not new i think.
Also it's not quite clear to translate it as "да". The word "хорошо" is a better variant.
The long and quite precise translation is
Хорошо, я согласен и мне легко это сделать, совершенно не напряжно