Need Help in this DS

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Need Help in this DS

by paritosh_b » Sat Dec 04, 2010 6:57 am
During a 7-year period the profits of Midas, Inc. changed by what percent from the sixth year to the seventh year?
(1) The profits of Midas, Inc. during the seventh year were 50 percent greater than the profits during the third year.
(2) The increase in the profits of Midas, Inc. was the same for each year during the 7-year period.

A) Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not.

B) Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not.

C) Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient.

D) Either statement BY ITSELF is sufficient to answer the question.

E) Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question,
OA:
C
Source: — Data Sufficiency |

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by Bharat » Sat Dec 04, 2010 11:11 am
Hi Paritosh,
we need to assess if we can identify % change in profit from 6th to 7th year.

Statement 1: informs the % change between 3rd & 7th year: NOT SUFFICIENT.
Statement 2: informs the % of change is same for each consecutive year: NOT SUFFICIENT.

However, if you put these two together: we know the change from 3rd thru 7th year & also that the change is uniform for each individual year: SUFFICIENT. [enough information to calculate the individual year % change]

Hence 1 & 2 together are sufficient & answer is [C].

Let me know if you have questions.

Regards,
Bharat.

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by goyalsau » Sat Dec 04, 2010 7:33 pm
paritosh_b wrote:During a 7-year period the profits of Midas, Inc. changed by what percent from the sixth year to the seventh year?
(1) The profits of Midas, Inc. during the seventh year were 50 percent greater than the profits during the third year.
(2) The increase in the profits of Midas, Inc. was the same for each year during the 7-year period.
Lets Assume Profit in every year as X

X1 - First Year, X2-Second year ................. X7 - Seventh Year

1) The profits of Midas, Inc. during the seventh year were 50 percent greater than the profits during the third year.

X7 (1.5) = X3

We don't know anything about X6 so insufficient.

2 ) The increase in the profits of Midas, Inc. was the same for each year during the 7-year period.

Clearly Insufficient on this own


Combining Statements Together.

Increase in profit is P

X1 + ----- First Year Profit.
X1 + P ----- Second Year.
X1 + 2 ( P ) ----- Third Year
X1 + 3 ( P ) ----- Forth Year
------
-----
-----
X1 + 6 ( P ) ----- Seventh Year.


X7 = (1.5) X3

X1 + 6P = (1.5) X1 + 2P
6P - 3P = 1.5 X1 - X1
3P = (1/2 ) X1

X1 = 6P

Now We Left with only one variable we can solve for change is X

Sixth Year Profit = X1 + 5P = 11 P ( X1 = 6P)
Seventh Year Profit X1 + 6P = 12P

Change is 1P on 11 or we can say 1/11 = 9.09 %

Answer C :wink:
Saurabh Goyal
[email protected]
-------------------------


EveryBody Wants to Win But Nobody wants to prepare for Win.

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by paritosh_b » Sat Dec 04, 2010 8:10 pm
Thanks a lot. :)
I was not able to figure out how both stat(1) and stat(2) are sufficient together.
I got it now.Thanks :)