Nathan, Rosephine and Sheena were given some lollipops. $\frac{1}{2}$ of Nathan\textquotesingle s number of lollipops was equal to $\frac{1}{5}$ of Rosephine\textquotesingle s number of lollipops. $\frac{1}{5}$ of Rosephine\textquotesingle s number of lollipops was also equal to $\frac{3}{5}$ of Sheena\textquotesingle s number of lollipops. If they had $780$ lollipops in total, how many lollipops did Sheena have?~\uline{~~~~~~~~~~}~ 
Overseas Competition->Knowledge Point->Counting Modules