David reads 80 pages every day.
Karen reads 25% more pages every day than David reads.
So, Karen reads
more pages. She reads a total of 80 + 20 =100 pages.
Rick reads 35% fewer pages per day than Karen. So, Rick reads
less pages than Karen. He reads 100 - 35 =65 pages
So, in total the tree friends read = 80+100+65=245 pages.
So, equation becomes
![245d=10000](https://img.qammunity.org/2020/formulas/mathematics/middle-school/f151qoblpj071paw9kv2200w1jdtsa23wu.png)