Alterego wrote:
A certain IT department of fewer than 15 people hires coders and systems administrators. Coders are paid $55,000 per year on average, while system administrators are paid an average yearly salary of $45,000. What is the ratio of coders to systems administrators?
(1) If two of the coders were made systems administrators instead, the yearly payroll for the IT department would be $535,000.
(2) If systems administrators' salaries were reduced by one-third, and coders' salaries were increased to $58,000, the department would save $57,000 in yearly payroll.
Let's drop the thousands and work with smaller numbers.
Denote by A the number of administrators and by C that of the coders.
(1) We can write the following equation:
55(C - 2) + 45(A + 2) = 535, which can be written as
11C + 9A = 111.
We have to keep in mind that
A + C < 15 and that A and C are positive integers.
Checking for possibile solutions under the given constraints, we find a single pair
A=5 and
C=6.Sufficient.
(2) Now we can write
55C + 45A - (58C+30A) = 57.We have to solve the equation
5A-C=19. Again, A and C must be positive integers and
A + C < 15.
We find a single pair of admissible solution,
A = 5 and
C = 6, only if we assume that there is more than one coder.
Otherwise, we could also have the solution
A = 4 and
C = 1. As the question talks about administrators and coders, it is reasonable to assume that there is more than one of each type.
Sufficient.
Answer D
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