22 bits
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Answer:
The flashdrive can hold 35389 400-pages-books
Explanation:
If
of a page occupies 1 kB of memory, we can calculate how much memory a book will take

Now that we know that a book average file size is about 266,67 kB, we calculate how many of them can a 9 GB flash drive hold.
To do the calculation, we have to know how many kilobytes are in 9 gigabytes.
There is 1024 kilobytes in a megabyte, and 1024 megabytes in a gigabyte, so:

Finally, knowing the average file size of a book and how much memory in kilobytes the 9 GB flash drive holds, we calculate how many books can it hold.

The flashdrive can hold 35389 400-pages-books, or 14155776 pages of typical text.
It’s real my easy you can use a calculator or an online converter. Or division
(111001)₂ = (1 × 2⁵) + (1 × 2⁴) + (1 × 2³) + (0 × 2²) + (0 × 2¹) + (1 × 2⁰) = (57)₁₀
(1100000)₂ = (1 × 2⁶) + (1 × 2⁵) + (0 × 2⁴) + (0 × 2³) + (0 × 2²) + (0 × 2¹) + (0 × 2⁰) = (96)₁₀
(1010101)₂ = (1 × 2⁶) + (0 × 2⁵) + (1 × 2⁴) + (0 × 2³) + (1 × 2²) + (0 × 2¹) + (1 × 2⁰) = (85)₁₀
(1001000)₂ = (1 × 2⁶) + (0 × 2⁵) + (0 × 2⁴) + (1 × 2³) + (0 × 2²) + (0 × 2¹) + (0 × 2⁰) = (72)₁₀