A company has 15 managers and 75 associates. The 15 managers have an

I solved this using average formula :

(15*120,000 + 75 * 30,000) / 90

= 45, 000

Answer B

However, with this approach I needed around 2 minutes. Is there a faster way?

Well, the answer is obviously B , BUT in order to solve the question faster and calculate easier let's try this approach :

AS you know some countries some times eliminate zeros in their currency because of high inflation in their countries , so we can apply this approach in order to solve the problem in a faster way

lets eliminate 3 zero's from the big numbers , so we have 120 $ instead of 120,000 $ and also 30$ instead of 30,000$

we are told that company has 15 managers with average salary of 120$ .... so total amount of salary will be 15*120= 1800$

Also, we are told that the company has 75 associates with average salary of 30$ .... so total amount of salary for those guys will be 30*75= 2250$

Final stage : for calculating the total average salary we have the sum of two groups of people divided by the total number of people : ( 1800+2250) / (75+15) = 4050/90 OR : we can cancel out

zero from denominator and numerator , so we have : 405/9 = 45 !!!!! by viewing to the answers ONLY option B fits .....

Took less than One minute....

Best Regards,

Answer = B = 45000

Average salary \(= \frac{15*120000 + 75*30000}{15+75} = \frac{15*120000}{90} + \frac{75*30000}{90} = 20000 + 25000 = 45000\)

Hi mehrdadtaheri92,

I like your thinking - that's a clever way to eliminate some of the "excess math" and make the calculations easier. To that end, what would have happened if you had eliminated ALL of the 0s... and used 12 and 3 (instead of 120 and 30)?

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

Let us ignore the last 3 zeros since they're common for all terms.
Total salary of 15 managers = 15 * 120 = 1800
Total salary of 75 associates = 75 * 30 = 2250
Total salary of company = 1800 + 2250 = 4050

Average salary of 90 employees = 4050/90
= 45
Let us put back the 3 zeros again
= 45000
Hence option B.

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MAGOOSH OFFICIAL SOLUTION:

The 15 managers have an average salary of $120,000. The sum of their salaries is:
sum = (average)*(number of salaries) = $120,000*15 = $1,800,000

The 75 associates have an average salary of $30,000. The sum of their salaries is:
sum = (average)*(number of salaries) = $30,000*75 = $2,250,000

When we add those two sums, we get the total payroll of all 90 employees.
$1,800,000 + $2,250,000 = $4,050,000

So, we have 90 employees, and together they earn $4,050,000, so the average is
average = $4,050,000 ÷90 = $45,000

Answer: B.

Dear Friend,

You are right of course , But dear friend Notice that eliminating 3 zeros can bring us simplicity enough to solve question fast.

So, I over looked to eliminate zero.... But , you are right my friend, Thanks...

hi LaxAvenger ,

Check out the below link. It might help.

https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2011/03 ... -averages/

Thanks!

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