# 19 - Calculate number of bits saved

1. How many bits are there per character?
```Given the below what would your answer be?
===========================================
An ASCII character in 8-bit ASCII encoding is 8 bits (1 byte),
though it can fit in 7 bits.
An ISO-8895-1 character in ISO-8859-1 encoding is 8 bits (1 byte).
A Unicode character in UTF-8 encoding is between 8 bits (1 byte) and
32 bits (4 bytes).
A Unicode character in UTF-16 encoding is between 16 (2 bytes) and 32
bits (4 bytes), though most of the common characters take 16 bits. This is the
encoding used by Windows internally.
A Unicode character in UTF-32 encoding is always 32 bits (4 bytes).
An ASCII character in UTF-8 is 8 bits (1 byte), and in UTF-16 - 16 bits.
The additional (non-ASCII) characters in ISO-8895-1 (0xA0-0xFF) would
take 16 bits in UTF-8 and UTF-16.```

It depends what the character is and what encoding it is in: (8 bits for extended ASCII)

Always 1 bit per character

Always 12 bits

Always 256 bits

2. In "Peter Piper picked a peck of pickled peppers" the total no. of characters is ….

23 (including spaces)

33 (spaces are never included in calculations)

44 (including spaces)

22 (excluding spaces)

3. In normal ASCII encoding a bit of text that had 44 characters (including spaces) would require:

1 bit per character making a total of 44 bits

10 bits per character making a a total of 44 x 10 = 440

4 bits per character making a total of 44 x 4

8 bits per character making a total of 352 bits

4. To recap: Each character in an ASCII file uses 7 bits, but most files use extended ASCII which is ___________________-

8 bits per character

4 bits per character

14 (double) bits per character

2 bits per character

5. To calculate the file size of an ASCII text file, count the nuber of characters, including spaces and that will be ______________

the number of bits in the file

the number of KB in the file

the number of bytes in the file

the number of MB in the file

6. Once you have found the number of bytes contained in a file, to find the number of bits you just need to:

None of the above

multiply the number of bytes by 8

multiply the number of bytes by 256

multiply the number of bytes by itself

7. The ASCII file size in bits =

number of characters

number of characters x number of bits

number of characters x 2

number of characters x 8

8. How many bits and bytes are in this sentence? "My name is Hannah"

30 bytes and 339 bits

None of these options apply

45 bytes and 280 bits

9 bytes and 78 bits

9. How many colours can be represented in an image with 8 bits?

None

256

33

25

10. The number of pixels in an image is worked out by: image width x image height (in pixels)

FALSE

TRUE