Q 124, OG 11

Oracio · Posted: Sat Sep 01, 2007 12:07 pm Post subject: Q 124, OG 11

Q: According to a car dealer's sales report, 1/3 of the cars sold during a certain period were sedans and 1/5 of the other cars sold were station wagons. If N station wagons were sold during that period, how many sedans, in terms of N, were sold:

A. 2/15N
B. 3/5N
C. 5/3N
D. 5/2N
E. 15/2N

The correct answer is D. My question, why can't i solve this problem using Kaplan's method of picking numbers. I pick 15 and come up with C as the answer, but thats obviously wrong.

keepsmilinyaar · Posted: Sat Sep 01, 2007 12:15 pm Post subject:

Even i read the question and got C as the answer but realising that the answer was D, I reread the question and realised i had made a mistake.

Notice the following part of the statement:
1/5 of the other cars sold were station wagons

Implies

Assume that the total number of cars is X
Sedan = (1/3)X
Othercars = (2/3)X
Station wagons = (2/3)X *(1/5) = (2/15)X = N
=> X = (15/2)N

Sedan = (1/3)X => (1/3) * (15/2)N
Sedan => (5/2) N

Hence the answer is D