#1482 and #392 Have incorrect answers


#1

Question: How many kilobytes in one gigabyte? (ID 1482)
Correct answer is stated as 1048576 but should be 1000000!
Question: How many bytes are in a kilobyte of RAM? (ID 392)
Correct answer is stated as 1024 but should be 1000!


Question #392 is wrong
#2

This has been corrected.


#3

Since bytes work using binary systems, the answers are NOT 1000000 and 1000. There stated answers are correct :slight_smile:


#4

After doing more research, as far as I can tell, Kilobytes and Gigabytes are 1000, and 1000000 respectively according to NIST.

A new prefix, kibi and gibi were created for 1024 and 1048576 respectively.


Question #392 is wrong
#5

Interesting, first I’ve heard of that. I don’t think kibi and all of those are commonly used anywhere though, so it makes sense I guess.


#6

People often use the convention that an uppercase K is 1024 (rather than 1000), since the normal “kilo” (1000) must be written in lowercase (otherwise you’d be referring to Kelvin, typically). So 1KB is 1024 bytes and 1kB is 1000 bytes. Because this is not official but just a convention which sprung up, the kibibyte (and mebi- and so on) was invented, which is unambiguously 1024-based rather than 1000-based. But when written out, the “kilobyte” is (strictly speaking) just 1000 bytes, since you’re clearly referring to the metric kilo instead of anything else.


#7

Thanks for the explanation, though I am curious about something. When were kibi, mibi, etc, created?


#8

Wikipedia -> search “kibibyte” -> https://en.wikipedia.org/wiki/Kibibyte

The binary prefix kibi means 2^10, or 1024; therefore, 1 kibibyte is 1024 bytes.

The unit was established by the International Electrotechnical Commission (IEC) in 1998, has been accepted for use by all major standards organizations, and is part of the International System of Quantities.

As far as I know, this international system of quantities is the closest thing to a universal standard we have. I’m not sure if, for example, China uses it (since they like to make their own version of everything, and in many cases that’s fine), but it seems widespread in the western world. I’ve seen the use of KiB quite a few times now, but then as a software engineer, I guess I’m more likely to see it than most.


#9

Ah awesome, thanks for explaining. It seems odd that I’ve never heard mention of them despite studying computer science, but always happy to expand my knowledge :slight_smile: