To understand why the calculated numbers of books are correct, let's break down the problem step-by-step:
-
Total Books: Kara owns a total of 35 books.
-
Percentage Calculation: The problem provides us with the percentages of books based on their page counts:
- 20% of the books have fewer than 100 pages.
- 80% of the books have 100 pages or more.
-
Calculating the Number of Books with Fewer Than 100 Pages:
- To find how many books correspond to 20% of the total, you multiply the total number of books (35) by 0.20 (which is 20% expressed as a decimal).
\[
0.20 \times 35 = 7
\]
This tells us that 7 books have fewer than 100 pages.
-
Calculating the Number of Books with 100 Pages or More:
- For the books with 100 pages or more, you do the same thing using the percentage of 80%. This can also be confirmed by calculating 80% of the total books.
\[
0.80 \times 35 = 28
\]
This tells us that 28 books have 100 pages or more.
-
Verification of Percentages:
- The sum of books should equal the total number of books:
\[
7 \text{ (fewer than 100 pages)} + 28 \text{ (100 pages or more)} = 35 \text{ (total books)}
\]
This confirms that our calculations are internally consistent.
Thus, the answer is valid and correctly describes the number of books Kara owns based on the provided percentages. So, Kara owns 7 books with fewer than 100 pages and 28 books with 100 pages or more.