David and karen have a goal to read 10,000 pages together by the end of summer.

david reads 80 pages every day.

karen reads 25% more pages every day than david reads.

david and karen agree that the model 180d = 10,000 will tell them how many days it will take them to read 10,000 pages, together, by the end of summer.

they invite rick to read with them to get to their goal faster. rick reads 35% fewer pages per day than karen.

which equation can be used to find how many days it will take david, karen, and rick to read 10,000 pages, together, by the end of summer?