NandishSS wrote:In a certain bookstore, 30 percent of the books that have been discounted are called bargain books and are priced below $4. If the bargain books make up 18 percent of the total number of books in the store, what percent of the books in the store are discounted?

A) 13%

B) 48%

C) 54%

D) 60%

E) 88%

OA:D

Source:GMATPrep EP2

Say the number of bargain books = B, discounted books = D, and the total number of books = N.

We need to find out (D/N)*100%.

So, as per the information,

B = 30% of D and B = 18% of N;

Thus, 30% of D = 18% of N => D/N = 18%/30% => (D/N)*100% = (18/30)*100% = 60%.

OA: D

-Jay

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Hi NandishSS,

This question can be solved by TESTing VALUES.

Let's start with 100 discounted books

30% of the books that have been discounted are called 'bargain books'

30% of 100 = 30 bargain books

We're told that the total number of bargain books = 18% of ALL the books in the store...

30 = .18(TOTAL books)

3000 = 18(TOTAL books)
1000 = 6(TOTAL books)
166 = TOTAL books

The question asks for the percent of the TOTAL books that are discounted books...

100/166 = 3/5 = 60%

Final Answer: D

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

NandishSS wrote:In a certain bookstore, 30 percent of the books that have been discounted are called bargain books and are priced below $4. If the bargain books make up 18 percent of the total number of books in the store, what percent of the books in the store are discounted?

A) 13%

B) 48%

C) 54%

D) 60%

E) 88%

We can let the total number of discounted books = d and let the total number of books in the store = n.

We need to determine what percent of the books in the store are discounted or d/n x 100 = ?

Since 30 percent of the books that have been discounted are called bargain books, bargain books = 0.3d

Since bargain books make up 18% of the total books in the store, bargain books = 0.18n

Thus, we can equate 0.3d and 0.18n and isolate d/n.

0.3d = 0.18n

30d = 18n

d/n = 18/30 = 3/5

Thus d/n x 100 = 3/5 x 100 = 60 percent.

Answer: D