A swim club that sold only individual and family memberships charged $

x+y=480,000
x= total revenue from individual memberships = Individual Memberships [i] * Individual Rate [r1]
y= total revenue from family memberships = Family Memberships [f] * Family Rate [r2]

(1) The revenue from individual memberships was 1/4 of the total revenue from memberships.

x= \(\frac{1}{4}\)*$480,000 = $120,000
x= i * r1 = i*$300 = $120,000 ==> i= 400 individual memberships

y= \(\frac{3}{4}\)*$480,000 = $360,000
y= f * r2 ==> two unknown variables, hence Not Sufficient.


(2) The club sold 1.5 times as many family member- ships as individual memberships.

x+y = $480,000; and r1=$300 ==> (i * $300) + (f * r2) = $480,000, where f = \(\frac{3}{2}\)i

(i * $300) + (f * r2) = (i*$300)+(\(\frac{3}{2}\)i*r2) = $480,000 ==> We still have two unknown variables and one equation, hence Not sufficient.

(1) + (2)

(1) i=400 memberships; and y=$360,000
(2) f= 1.5i = \(\frac{3}{2}\) * 400 = 600 family memberships

y= $360,000 ==> y = f*r2 ==> 600 * r2 = $360,000
r2=$600, thus Sufficient, Answer is C.

Solution:

Statement 1: The revenue from individual memberships was 1/4 of the total revenue from memberships
Revenue from selling individual memberships = 480,000 / 4 = 120,000
Revenue from selling family membership = 480,000 - 120,000 = 360,000
- Insufficient to find the selling price of family membership

Statement 2: The club sold 1.5 times as many family member- ships as individual memberships
We don't know the total memberships sold or individual membership sold
- Insufficient to find the selling price of family membership

Combining statement 1 and 2:
Number of individual membership sold = 120,000 / 300 = 400
Number of family membership sold = 1.5 * 400 = 600

Charge for family membership = 360,000 / 600

Thus Statement A & B together are sufficient, Answer C

The answer is C. Solution is in the attached picture

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.