Cyrus has been contracted to write a 500 page book.  On his first day, he writes 25 pages and twice that amount on the second day.  On the third day he is able to write twice the amount that he did on the second day.  On the fourth day, he gets writer's block and is only able to write 10 pages.  How many more pages does he need to write?
On the second day he wrote twice the amount as the first day, which was 25 pages so 2*25 = <<2*25=50>>50 pages
On the third day he wrote twice the amount as he did on the second day, which was 50 pages so 2*50 = <<2*50=100>>100 pages
The first day he wrote 25, then 50, then 100 and 10 on the fourth day for a total of 25+50+100+10 = <<25+50+100+10=185>>185
He needs to write 500 pages and has written 185 which means he has 500-185 = <<500-185=315>>315 more pages to write
#### 315