Supergmatgirl wrote:
Can you please elaborate?
One has to understand the concept of weighted averages pretty well to understand my solution.
The point of a weighted average is to know how much weight to give these two individual groups, the managers and the directors.
Statement 1 tells how the managers' salaries relate to employee average but there is no information about how the directors' salaries relate to the employee average.
Insufficient
Eliminate A & D
Statement 2 tells how the directors' salaries relate to employee average but there is no information about how the managers' salaries relate to the employee average.
Insufficient
Eliminate B
Statements 1 and 2 together:
The manager average is 5000 less than the combined average. The director average is 15000 greater than the combined average. The difference between the manager average and the director average is 20000.
If there were an equal number of managers and directors they would each be 10000 off of the combined average - that would be a 50/50 weighting.
But the combined average is closer to the manager average, so there are more managers than directors. Use the above three numbers to know how much: the difference is 20000, and the combined average is three-quarters of the way towards the manager average.
Hence, 3/4 of the employees are managers & 1/4 are directors.
Sufficient.
Hence C.