Need a little help please

[fambrini]

The bookstore at Union College buys used text-books from students and offers them for resale at a price that is a fixed percent of the original price of the book when it was new, regardless of the title of the book or its condition. If a new freshman chemistry book sells for $40, at what price should it be offered for resale?

1) A student saves $7.50 by buying a used rather than a new freshman biology book.

2) A biology book that costs $30 when new is offered for resale at $22.50

OA: B

I'm having trouble to find out why statement 1 is not sufficient.

Thanks,
Fambrini

[fiza gupta]

given: chemistry new book $40

1) after resale a student saves $7.50 in a biology book
its a biology book we don't know its final price nor fresh price
we cannot find the percentage.

its not sufficient because in question price of chemistry book is mentioned not biobook's
if instead of chemistry, bio book price were given then the statement would have been sufficient
INSUFFICIENT

2)bio book = $30 , resale price: 22.50
we can find the %
SUFFICIENT

SO B

[Jay@ManhattanReview]

Fambrini,

The question says that the resale price is a fixed percent of the original price.

=> Resale price = Original price - % discount on Original price

So, we ned to know two data: Original price and % discount on Original price

From S1, though we know discount = $7.50, it is not a % discount and is applicable for the bio book and not for Chem book. We cannot calculate 5 discount. So it cannot help us!

From S2, we know the original price and the resale price of the SAME book, Bio. So, we can calculate discount = 30 - 22.50 = 7.50, and then % discount.

=> % discount = (7.50/30)*100% = 25%

=> Resale price of Chem book = 40 - 25% of 40 = $30. Sufficient!

Hope this helps!

-Jay

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