Problem Solving Territory: 700+ questions only..............

He definied x = X / 100 It makes sens as x < X

Actually, he could set y=(1+X/100)(1-X/100)

Hey fig, that's fine.
But i said the price is decreased by 180 and not that the decreased price is 180.

So how can he write cp(1+x)(1-x) =180
CP(1+x)(1-x) is the reduced price where as 180 is the reduction in the prize.

The correct expression would be
CP(1+x)(1-x) = P-180, where P= initial price and x=X/100.

Absolutly

DAMN! 2 days to go and I'm crapping up!!!

Okay.. here goes.

CP - CP(1-x^2) = 180
=> CP*x^2 = 180 --(1)

CP(1-x^2) - CP(1-x^2)(1-x^2) = 153
=> CP(1-x^2)x^2 = 153 --(2)

Using (2)/(1), we get
(1-x^2) = 153/180
=> x^2 = 1 - 153/180 = 27/180 = 3/20 --(3)

From (1) and (3) we get,

CP(3/20) = 180 => CP = 1200.

Howzzat? Don't tell me I'm wrong again

paddyboy, will u go on this monday for the GMAT?

Tuesday actually, but I'm not counting it...

I c Best of luck for it :D U are on the right track for it

Next week seems to be the week for at least 3 of us

Who's the third?

And dude, Best of luck! I'm sure we'll maul the GMAT

Or as Futuristic put it, "Spread it out on the lawn and jump on it with hob-nailed boots!"

I prefer to PM u it

could you also give the answer choices. that way we can test the fastest way to go about this..

Folks, this is again based on the basic funda of Percentages.

If a number is increased by x% and then decreased by x% there always will be a decrease.

It is given that the price (P)of the article is increased by x% and then decreased by x%. So the price will definitely decrease. Let the price decrease by y%

So clearly it is given that the price is decreased by 180 $.
Hence y%(P) = 180.............................(1)
Now the price of the artice is P-180. Since that same change is applied again on the present price this also will decrease by the same y%
Clearly it is given that the present price is decreased by 153$
Hence y%(P-180) = 153.....................(2)

From (1) and (2)
y%(180) = 27

ie y = 15.

Substituting the value of y in (1) we get
15%(P) = 180
Hence P=1200.

Now since u know the concept , u can use the options given in the exam to solve the questions like these.

Let's take 1200 as our first option
Initially the price is reduced by 180.

So the present price is 1020.

Now if 180 is the decrease on 1200, calculate the proportinate decrease on 1020.....

So i mean 1200------180
1020------??
ie (1020/1200)180 = (102/120)180 =153 which is exactly the second decrease in the given question..

Hence 1200 must be the answer........

I think i am lucid

Ok folks, let's get into the next question.........

2.

Hey, what happened?

Kevin, yezz, paddyboy,......... where r u?

cicerone all of them are drinking beer !!!

CE=1, not sure on how to calculate CD

hey, I know this problem has to be solved based on similarity of triangles. But finding it difficult to identify which triangles need to be compared.

Cicerone, great initiative. Please keep posting questions.

Answer pleaseeeeeeee