Kara owns a total of 35 books. Out of these, 20% have fewer than 100 pages, which means:
\[ 0.20 \times 35 = 7 \]
So, 7 of Kara's books have fewer than 100 pages.
The remaining 80% have 100 pages or more, which means:
\[ 0.80 \times 35 = 28 \]
Thus, 28 of Kara's books have 100 pages or more.
In summary, Kara owns 7 books with fewer than 100 pages and 28 books with 100 pages or more.