Below is the answer to yesterday’s GMAT Challenge Question!
Question
A restaurant pays a seafood distributor d dollars for 6 pounds of Maine lobster. Each pound can make v vats of lobster bisque, and each vat makes b bowls of lobster bisque. If the cost of the lobster per bowl is an integer, and if v and b are different prime integers, then which of the following is the smallest possible value of d?
(A) 15
(B) 24
(C) 36
(D) 54
(E) 90
Answer
Let’s start by finding the cost of the lobster, per bowl, in terms of the variables given (d, v, and b).
(d dollars/6 pounds) x (1 pound/v vats) x (1 vat/b bowls) = (d/6vb).
The problem states that this value, the cost of the lobster per bowl, or (d/6vb), is an integer. In other words, d is divisible by 6vb. To make d as small as possible, we need to make 6vb as small as possible. Since v and b are different prime integers, the smallest value of 6vb is 36 (using the two smallest prime integers, v = 2 and b = 3, or v = 3 and b = 2).
In order to make the cost of the lobster per bowl an integer, d must be divisible by 36. In other words, d must be a multiple of 36. What’s the smallest possible multiple of 36? The smallest multiple of 36 is 36.
The correct answer is C, 36.
# posted by Clear Admit @ 10:20 am in GMAT Tips, Workbook Wednesdays