Data Sufficiency

1. Is x> y ?

a) ax>ay
b) a(square)x > a(square)y


2. if the perimeter of a square region S and the perimeter of the circular regio C are equal, then the rati of S to the area of C is closed to ...?

3) If n and k are integer whose product is 400 which of the following must be true

a) n+k>0
b)n notequal to K
c) either n or k is a multiple of 10
d)if n is even k is odd
e)if n is odd then is even

#1. IMO B

Is x > y?

1. ax > ay

If a is +ve, then x>y. Yes
If a is -ve, then x<y. No
Insufficient.

2. a^2 * x > a^2 * y

Regardless of a as -ve or +ve, a^2 will always be positive. So, inequality sign does not change. x > y.
Sufficient.

#2. Can you post exact question and answer choices?

#3. n * k = 400

A. n and k could both be -ve. n=k=-20. n*k=400, but n+k < 0. Cannot be true.
B. n not equal to k. n=k=20 is possible. Cannot be true.
C. This is true.
D. If n is even, k is odd. May not be true always. n=k=20 is possible.
E. if n is odd then is even. Again same as D. Cannot be true.

Hi,

For Q3,
Choice E - If N is Odd then K must be Even is True. Because N*K=400 (Even). Therefore atlest N or K must be even.

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papgust wrote:#1. IMO B

Is x > y?

1. ax > ay

If a is +ve, then x>y. Yes
If a is -ve, then x<y. No
Insufficient.

2. a^2 * x > a^2 * y

Regardless of a as -ve or +ve, a^2 will always be positive. So, inequality sign does not change. x > y.
Sufficient.

#2. Can you post exact question and answer choices?

#3. n * k = 400

A. n and k could both be -ve. n=k=-20. n*k=400, but n+k < 0. Cannot be true.
B. n not equal to k. n=k=20 is possible. Cannot be true.
C. This is true.
D. If n is even, k is odd. May not be true always. n=k=20 is possible.
E. if n is odd then is even. Again same as D. Cannot be true.

Hi
C.it can not be true ,n=16,k=25
E.It will be always true.(product of odd and even always gives even no.).400 contains the odd factor

Whatever ST-1 & ST-2 are same. Cut the a or a^2. ANS: D