Sally reads 10 pages of a book on weekdays and 20 pages on weekends. If it takes 2 weeks for Sally to finish her book, how many pages that book has?
Two weeks has 5*2=<<5*2=10>>10 weekdays.
Two weeks has 2*2=<<2*2=4>>4 weekends.
On weekdays, she reads 10*10=<<10*10=100>>100 pages in total.
On weekends, she reads 20*4=<<20*4=80>>80 pages in total.
So the book has 100+80=<<100+80=180>>180 pages.
#### 180