GMAT PREP I WORD TRANSLATION

[pkw209]

Hey all,

Couldn't figure this one out. Got fewer # of equations than # of variables so thought the answer was E. brief explanation would be appreciated. Thanks!

64) Each employee is either a director or a manager. What % of the employees are directors?

a. The average salary of managers is $5000 less than the average of all employees
b. The average salary of directors is $15000 greater than the average of all employees

[papgust]

IMO C

1) Avg sal of Mgr = Avg sal of ALL - 5000. We don't know about directors. Insufficient.

2) Avg sal of Dtrs = Avg sal of ALL + 15000. We don't know about managers. Insufficient.

Combined,
You need to find the percentage here. If you are asked to find the number of managers or directors, then it would be E.

If the overall average is near an entity (In this case, managers and directors are entities), then the number of that entity is larger.
MGR-----Overall Avg--------------Directors
5000---- OVERALL -------------- 15000

Distance b/w managers and directors is 20000 units. Distance b/w managers and Overall Avg is 5000. Distance b/w Directors and Overall Avg is 15000.

So, the percentage of directors is 5000/20000 = 1/4.

Sufficient.