Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Over the summer break you went on a long trip and have painstakingly collected a

ID: 1995821 • Letter: O

Question

Over the summer break you went on a long trip and have painstakingly collected a 1,000 Gigabytes (1 Terabyte) worth of videos on your internet enabled camera. To avoid losing them, you'd like to back the data up on to a computer at your home in prairie View. You have two options: Option A: Send the data over the internet to the computer in prairie view. The data rate for transmitting information across the internet from your hotel to prairie view is 1 megabyte per second. That's because you have decided to use the hotel's free WiFi in the lobby rather than paying for a more expensive in-room connection that guarantees you a minimum of 10 Megabytes per second. Option B: Copy the data over to a set of disks, which you can do at 100 Megabytes per second. Then rely on the US Postal Service to send the disks by mail, which takes 7 days. Which of these two options (A and B) is faster? And by how much? Option C: Suppose now you decide to splurge and choose to pay for the high speed connection at the hotel. Which option is faster now? And by now much?

Explanation / Answer

Total data to be transmitted: 1000 Gigabytes = 1000 X 10^9 bytes

a. Rate of transmission - 1 megabyte per second = 10 ^6 bytes per sec which means 10^6 bytes would take 1 sec. Therefore 1000 X 10 ^9 bytes would take ( 1000X10^9)/ (10^6) = 1000X1000 sec.

No. of hours in a day = 24X60 X 60 sec = 86400 sec. Therefore, 1000 X 1000 sec are equivalent to 11.6 days

Hence it would take 11.6 days to transmit the data.

b. Rate of copying data: 100 megabytes per sec = 100 X 10 ^6 bytes per second.

The time that would be needed to copy 1000 gigabytes of data would be: ( 1000 X 10 ^ 9 ) / ( 100 X 10 ^ 6 ) = 10^4 sec

The no. of days that are equivalent to 10^4 sec = (10^4)/(86400) = 0.11days

The total time needed by second method would be : time needed to copy the data + postal service time = 0.11 + 7 = 7.11 days.

From the above, we can conclude that option B is faster ( since it takes 7.11 days when compared to option A which takes 11.6 days ). Option B is faster by 4.49 days.

c. The speed of high speed internet at hotel is : 10 mega bytes per sec.

To transmit 1000 Gigabytes, the time needed would be : (1000 X 10 ^9)/ ( 10 X 10^6 ) = 10 ^5 sec

This is equivalent to : ( 10 ^ 5) / 86400 = 1.15 days

Hence this is the fastest of all.