### A good answer might be:

64K bytes: 216 = 2(6 + 10) = 26 × 210 = 64K

# More About Patterns

Number of Bits | Number of Patterns | Number of Patterns as power of two
--- | --- | ---
1 | 2 | 21
2 | 4 | 22
3 | 8 | 23
4 | 16 | 24
5 | 32 | 25
6 | 64 | 26
7 | 128 | 27
8 | 256 | 28
9 | 512 | 29
10 | 1024 | 210

Many calculations involving bit patterns use the following familiar fact of arithmetic. (Although the fact is familiar, confusion is even more familiar. Be sure you know this factoid.)

> 2(N+M) = 2N × 2M

It is not too much work to extend the table, as shown at right. You can always make this table from scratch, but memorizing a few key values does not hurt.

The numbers of patterns that can be formed with 10 or more bits are usually expressed in terms of kilobytes (= 210) or megabytes (= 220). For example, how many patterns can be formed from 24 bits?

> 224 = 24 × 220 = 16 Meg

The power of two (24) splits into a small part (24) and a part that has a name (220 = Meg). This is a useful trick you can use to amaze your friends and impress employers.

Some audio cards use 12 bits to represent the sound level at an instant in time (12 bits per sample). How many signal levels are represented?

> 212 = 22 × 210 = 4K levels

### QUESTION 7:

You have a choice between a graphics card that uses 6 bits to represent colors, or one that uses 8 bits to represent colors. The 8 bit board is somewhat more expensive than the 6 bit board. Which should you choose?