Clarice is reading a magazine. The number of pages she has read to the number of pages she has not read is $$1 : 5$$. If she reads another $$80$$ pages, the number of pages she has read would become $$70 \%$$ of the total number of pages. How many pages are there in the magazine?~\uline{~~~~~~~~~~}~ 
Overseas Competition->Knowledge Point->Combinatorics->Patterns of Figures->Change of Quantity