trouble with percentages

fret_wimp2

feel really stupid asking this but i guess its even more stupid to sit here in ignorance!

I work in a reasonably technical job but last week i got a question i couldnt systematically work out the answer to. The question is:

there are 120 thousand files on a server taking up about 70GB of space.
how much space will 5 thousand files take up?

I could guesstimate in my head but i could not write down systematically how to work this out.

I need help with:
1. how to work out the above problem.
2. a decent site that can help me re-learn everyday mathematics.

Thanks all

Plazaman

70Gb divided by 120,000 = 0.00058333Gb = Space for 1 file

0.00058333Gb x 5000 = 2.916665Gb

Ouch, now my brain hurts.....

Fremen

Maths is all about knowing little tricks. If you know the right trick for the right situation, problems can be really easy. If you don't know the trick, you can struggle.

Here's the trick you need (assuming of course all files are of a similar size).

120 thousand files -> 70GB

Therefore,

1 thousand files -> 70/120 GB

so

5 thousand files -> 5*70/120 GB

Instead of trying to find out the storage for five thousand files directly, you work it out for one thousand, then multiply that by five - you solve two easy problems instead of one hard one.

amen

a bit off thread but you are assuming all files are the same size and they might not be. You could have a single 40GB file and 119,999 smaller files

LeixlipRed

Well you can't attempt this question unless you assume they're the same size. But yes, in reality all the files would be different sizes.

fret_wimp2

The files are data feed files, all within a few kb of each other so thats not an issue. Your posts have all helped me out though and were accurate, so thank you all very much. I appreciate it.