Which is the best name for the part of the figure identified by the arrow?

Klein read 30 pages of a book on monday and 1/8 of the book on tuesday. he completed the remaining 1/4 of the book on wendesday. how many pages are there in the book?

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

Add the fractions and simplify 1/2+ 1/3