neeti2711 wrote:A merchant paid $300 for a shipment of x identical calculators. The merchant used 2 of the calculators as demonstrators and sold each of the others for $5 more than the average (arithmetic mean) cost of x calculators. If the total revenue form the sale of the calculators was $120 more than the cost of the shipment, how many calculators were in the shipment?
(A) 24
(B) 25
(C) 28
(D) 30
(E) Cannot be determined
Total revenue = total cost + 120 = 300+120 = 420.
We can plug in the answers, which represent the number of calculators.
The correct answer almost certainly is a factor of 300.
Only B (25) and D (30) are factors of 300.
Since D implies an average cost of $10 per calculator -- a nice, round number -- we should start with D.
Answer choice D: 30
Average cost per calculator = 300/30 = 10.
Since 2 calculators are used, 28 are sold.
Selling price = average cost + 5 = 10+5 = 15.
Revenue from 28 calculators sold for $15 each = 28*15 = 420.
Success!
The correct answer is
D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3