Question

Hi,

Can someone check this for me please..

18 MB of data are to be transmitted over a a megabyte per second connection. How long should the complete transaction take, to the nearest 0.1s.

Size of file / data rate so,
18MB x 10^6 x 8 bits = 144,000,00

4 megabits per second = 4 x 10^6 = 4,000,000 bits per second

so the download time will be
144,000,000 / 4,000,000 = 36 seconds

my answer is 36 seconds is that right

next ,....

a 50 MB file compressed using a ratio of 10 what is the compressed file size

50MB / 10 = 5 MB

Is this correct ???

Thanks you

Answer 1

You have to double check the question:

"18 MB of data are to be transmitted over a a megabyte per second connection"

Is it "a" mega<i>byte</i> connection" or is it "4 mega<i>bit</i> connection"?

Answer 2

Hi

Sorry wasn't too clear

This should read 18MB of data are to be transmitted over a 4 megabits per second connection ... how long would it take to complete the transaction

Answer 3

to the nearest 0.1 s

Answer 4

For the second part of your question...

Compressed file size = uncompressed / compression ratio

so

Compressed file size = 50MB / 10

Compressed file size = 5MB

I think

Answer 5

No, incorrect.

Be carefull with this, your:

18MB x 10^6 x 8 bits = 144,000,00

Should in fact be:

18mb x 2^20 x 8 bits = 150,994,994

Your second part is correct, so its

4 megabits per second = 4 x 10^6 = 4,000,000

Answer:

150994994 / 4000000 = 37.75 seconds.