Hi GmatGreen,

The average formula is one of a variety of standard formulas that the GMAT will expect you to know and use. Sometimes, average formula questions include lots of variables; in this question, we're given lots of numbers to work with and then we're asked to solve for one variable. Here's what it takes to answer the question:

We're told that the average salary of 15 people = $20,000

Sum/15 = $20,000

The Sum of the 15 people = 15($20,000) = $300,000

Then we're told the salary of 5 people = $25,000 each and the salary of 4 of the people = $16,000 each

5($25,000) = $125,000
4($16,000) = $64,000

Now we know that those 9 people account for a total of $189,000 of salary

The question asks for the average salary of the remaining employees.
We know that there are 6 employees remaining
We also know that the remaining money = $300,000 - $189,000 = $111,000

$111,000/6 = $18,500

Final Answer: B

GMAT assassins aren't born, they're made,
Rich