20. DS, in a work force, the empolyees are either managers or directors. What is the percentage of directors?
a) the average salary for managers is $5,000 less than the total average salary
b) the average salary for directors is $15,000 more than the total average salary
answer is C)
Let x = percentage of directors and 1-x = percentage of managers,
A = average salary for managers and B = average salary for directors
I listed two equations based on the two conditions:
B+5000 = [A*x + B*(1-x)] / (x + 1-x)
A-15000 = [A*x + B*(1-x)] / (x+1-x)
2 equations, 3 unknowns. Shouldn't the answer be E? | 
