A telecommunications companys stock fell 10% last month, while a riva

Let the telecommunications company’s stock value at the beginning of last month be x which fell 10% last month = 0.9x

And rival company’s stock at the beginning of last month is Y, which increased by 10% = 1.1Y

The rival company’s stock value today is what percentage of the telecommunication company’s stock value at the beginning of last month = 1.1y is what percentage of X

Statement 1: The rival company’s stock was valued at $42 per share at the beginning of last month.
Y = 42
Increase = 42*1.1 = 46.2
We need to know 46.2 is what percentage of X
=> 46.2*100/X
No value of X (insufficient)

Statement 2: The dollar amount of the rival company’s stock increase was 90% as much as the dollar amount of the decrease in the telecommunication company’s stock.
Increase in rival stock = 0.1Y
Decrease in telecommunication company stock = 0.1x
0.1y = 0.9*0.1x
0.1y = 0.09x
X/y = 1.111/1 or y/x = 0.9
We want the value of 1.1y/x*100
Putting values.
1.1*y/x*100
1.1*0.9 = 0.99
(Sufficient)

Answer is B

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TC stock fell last month = 10% ; Today, the stock value of the telecommunication company =0.9x=0.9x
rival's stock increased last month = 10% ; And, the stock value of it’s rival company, today =1.1y=1.1y


1.1y = m% * 0.9x
m=?

St1: rivals stock value, y = $42
The value of "x" we don't know ; Not Suff.

St2: 0.1*y = 0.9* 0.1 * x
Thus we can find the value of y / x = 0.9
Sufficient


Thus, the correct answer is Option B.

Ans : B , imo

------------------ ----------Last Month----------------------This month-------

--Telecom Stock -----------S--------------------------------0.9 S ---

--Rival Stock---------------R--------------------------------1.1 R----

Ques is (1.1 R / S ) * 100 = ?

So if we get the value of R?S.. we can get the final value .



Statement 1: The rival company’s stock was valued at $42 per share at the beginning of last month.

No info about S . so NOT SUFFICIENT

Statement 2: The dollar amount of the rival company’s stock increase was 90% as much as the dollar amount of the decrease in the telecommunication company’s stock.

0.1R = 0.9 (0.1)S
So we can find R/S and the final value . Hence SUFFICIENT

So ans is B .

A telecommunications company’s stock fell 10% last month, while a rival company’s stock increased by 10%. The rival company’s stock value today is what percentage of the telecommunication company’s stock value at the beginning of last month?

Price of Company stock at the start of month, \(P_c = x\)
Price of Company stock at the end of month, \(P_c' = 0.9x\)
Price of rival Company stock at the start of month, \(P_{rc} = y\)
Price of rival Company stock at the end of month, \(P_{rc}' = 1.1y\)

\(\frac{P_{rc}' - P_c}{P_c} * 100 = \frac{1.1 y - x}{x} * 100\) = ?
\(\frac{P_{rc}'}{P_c} = \frac{1.1 y}{x} = ?\)
\(\frac{y}{x} = ?\)

(1) The rival company’s stock was valued at $42 per share at the beginning of last month.
y = 42
x = ?

INSUFFICIENT.

(2) The dollar amount of the rival company’s stock increase was 90% as much as the dollar amount of the decrease in the telecommunication company’s stock.
1.1y - y = 0.9 * (x - 0.9x)
0.1y = 0.9 * 0.1x
\(\frac{y}{x} = 0.9\)
\(\frac{P_{rc}'}{P_c} = 1.1 * 0.9 = 0.99\)

SUFFICIENT.

Answer B.

Kindly see the attachment.
Need to find the ratio of prices of TC and rival company
B