PERCENTS KILLING ME PLEASE HELP!!! RON

[Guest]

This is from princeton review data sufficiency.

By what percent was the price of a certain tv set discounted for a sale?
1) the price of the tv set before it was discounted for the sale was 25 percent greater than the discounted price
2) the price of the television set was discounted by 60 for the sale

the answer is A.

Interpretation of First Statement
price before discount =x
price after discount = .75 x

or

price before discount =1.25 x
price after discount= x

or
price before discount=x
price after discount =1.25x

I dunno. I'm confusing myself!!!! Please help. :?:

[Guest]

This is from princeton review data sufficiency.

By what percent was the price of a certain tv set discounted for a sale?
1) the price of the tv set before it was discounted for the sale was 25 percent greater than the discounted price
2) the price of the television set was discounted by 60 for the sale

The trick to these problems is understanding when stems give information that will setup a ratio. No matter what positive values you put in for X, the percent change will stay the same.

We know that:
% change = (Discount Price - Regular Price) / Regular Price

1) X = Discount Price 1.25X = Regular Price

(X - 1.25X) / (1.25X) = -(.25X) / (1.25X) = -.20

Notice that no matter what number you put in for X, you will always get -.20
SUFFICIENT

2) This answer tells us that the price of the TV was discounted by $60 during the sale.
You don't know how much the TV originally cost. The TV could've been $100,000 or the TV could've been $100. The discount of $60 will make a huge different in the percent discount you receive.
INSUFFICIENT
(If you decided to do this stem first, make sure you don't let this information impact your evaluation of the first statement!)


I hope this helps explain things.

[Guest]

Interpretation of First Statement

price before discount =x
price after discount = .75 x

or

price before discount =1.25 x
price after discount= x

or
price before discount=x
price after discount =1.25x

I dunno. I'm confusing myself!!!! Please help. :?:

To answer your question:

The example says that the original price was 25% greater then the discount price.

Discount Price = X

Original Price = Discount Price + .25(Discount Price)
Original Price = X + .25X
Original Price = 1.25X

If you're still confused just plug in numbers to see what happens.
Plug in 100 for X and see which makes sense.

price before discount =x $100
price after discount = .75x $75

The original price was 25% greater then the discount price.
25% of the discount price = 75/4 = 18.75 added to 75 = 93.75 Incorrect

price before discount =1.25x $125
price after discount= x $100

25% of discount price = 100/4 = 25 added to 100 = 125 Correct

price before discount=x $100
price after discount =1.25x $125

25% of discount price = 125/4 = 31.25 added to 125 = 156.25 Incorrect (and more expensive then the original price of the item!)

[rfernandez]

Good to see you guys helping each other out. Nice solutions.

[rockyrashidi]

Hi Guys,
I am a newcomer here and i am not sure if this is the right place to ask, I have a GMAT problem here, and its not that hard apparently but maybe I am stupid .
By what percent was the price of a certain television set discounted for a sale?
(1) The price of the television set before it was discounted for the sale was 25 percent
greater than the discounted price.

(2) The price of the television set was discounted by $60 for the sale.


ok so I keep getting E, now can someone just call me stupid and explain to me, and make me understand what this 25% greater is. I just dont get this concept. We are saying the D(1.25) = O , with O being original price and D being discount price. If Original price is 25% greater than the Discounted price, then how is it possbile that the discount is 20%?? thats what is driving me crazy.

How is original price greater by 25%, if discount is 20% off, should the original price be 20% more than the discounted price???
sorry if i sound stupid but this got me very frustrated

[RonPurewal]

as per the forum rules, we need a citation of the original source of this problem before we can discuss it here.

thank you.