VJesus12 wrote:24 computer hackers can scan and infect 10 computers in 5 hours. If this group of hackers wants to scan and infect 20 computers in 8 hours, how many new computers hackers do they need to recruit and join their team in order to accomplish this task, assuming all hackers work at the same rate?
A) 0
B) 6
C) 8
D) 10
E) 16
Use the following equation:
(workers)(time) / output = (workers)(time) / output
In the equation above:
Workers and time are INVERSELY PROPORTIONAL.
As the number of workers
increases, the amount of time required to produce the same output
decreases.
Workers and output are DIRECTLY PROPORTIONAL.
As the number of workers
increases, the amount of output also
increases.
Time and output are also DIRECTLY PROPORTIONAL.
As the amount of time
increases, the amount of output also
increases.
In the problem above:
(24 hackers)(5 hours)/(10 computers) = (x hackers)(8 hours)/(20 computers)
12 = (2/5)x
60 = 2x
x = 30.
The number of hackers increases from 24 to 30.
Thus:
Number of additional hackers = 30-24 = 6.
The correct answer is
B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
