One computer can upload 100 megabytes worth of data in 3 seconds. Two computers, including this one, working together, can upload 1300 megabytes worth of data in 30 seconds. How long would it take for the second computer, working on its own, to upload 100 megabytes of data? Options:  A) 6  B) 10  C) 9  D) 11  E) 13

Rationale: since the first computer can upload 100 megabytes worth of data in 3 seconds then in 3 * 10 = 30 seconds it can upload 10 * 100 = 1000 megabytes worth of data , hence the second computer in 30 seconds uploads 1300 - 1000 = 300 megabytes worth of data . the second computer can upload 100 megabytes of data in 10 seconds . answer : b .
Answer: B