Friday, September 12, 2008

12th september Gre Quants Question

1. If n is a odd positive integer, then
Col A: (-2)^((n+1)/2)
Col B: (-2)^((n-1)/2)

2.

Given equation of the parabola as y = 2x-x^2.
Col A: t
Col B: 2s-s^2

3. A person has 5 pairs of sox and each are differently colored. If a person picks one pair of sox simultaneously, what is the probability that it is of same colored pair?

4. How many different 5 digit numbers can formed, such that 1st and last place should be filled up with odd number.
A.25000
B.20000
so on….

5. If (4/7) = (4+s)/(7+t), then
Col A: s
Col B: (4t/7)

6. If x(x-15/7)(x+4)(x+3)=0, then what is the product of maximum and minimum value of x?

7. If a square of 125cm3 is fit into a cylinder, then what should be the minimum value of the volume of the cylinder?

8. If (a^2 @ b^2) = a^2-b^2 & (a^2 # b^2) = a^2+b^2, then
Col A: (2^2@-2^2) # (3^2@-3^2)
Col B: 0

9. The Harmonic Mean of 10, 20 is ………..

18 comments:

Anonymous said...

1.D
2.B
3.1/9
4.6720
5.C
6.-60/7
7.98.214
8.C
9.40/3

Please check the quant database for the diagram of the 2nd Question


Please correct me if iam wrong anywhere

Anonymous said...

hey can u explain how did u solve 7th question ??

Anonymous said...

Hi chirag,

for the 7th question.....square with 125cubic cm is cube.

For the cube to fit in the cylinder, the diameter of the cylinder should atleast be 5 and the height of the cylinder should atleast be 5

Therefore, r=2.5 and h=5

Minimum volume of a cylinder = pie * r^2*h
=3.14*(2.5^2)*5=98.214

Please correct me if iam wrong anywhere

Anonymous said...

Hi chirag,

i made a mistake

the diameter of the cylinder should atleast be the diagonal of the square

Diameter= 5(sqrt2)
radius=5/(sqrt2)

Volume=3.14*(25/2)*5 = 196.43

Please let me know in case of any Issues

Anonymous said...

can anyone explain me the second ques briefly...

i am obfuscated.....

Anonymous said...

Hi pradeey,

from the diagram,

y=2x-x^2 only at the apex of the parabola...for all the points inside the parabola,,,y will be less than 2x-x^2

Given point (s,t) is inside the parabola,
Therefore,t < 2s-s^2

Answer is B

Please let me know in case of any issues

Anonymous said...

if a cube is to fit into a cylinder, the min height of cylinder must be equal to height of cube=5
where as the radius of cylinder on top surface must be half of hypotenuse of square surface of cube, hypotenuse=5*sqrt(2)
r=5*sqrt(2)/2=7.07/2=3.535,
vol of cylinder=pie*r^2*h,=196.19

Anonymous said...

question no 4 answer is 25000

there are five places to b filled _ _ _ _ _

first and last places can b filled in five ways 5*5(ie 1,3,5,7,9)

second third and fourth places can be filled in 10 ways (0,1,2.....9)


therefore the answer is 5 * 10 * 10 * 10 * 5

=25000

Anonymous said...

pls explain 9 th question

Anonymous said...

Hi senthil,

for the 9th question

HM = 2/((1/a)+(1/b))

Use this formula,u vl get the answer

Please correct me if iam wrong

Ganta Pothuluri Reddy said...

please solve 3rd ?...i am confused

Shekhar Agrawal said...

Hi Ganta
For Ques 3rd

There are 5 pairs , i.e. 10 socks. You have picked 2.
Lets start solving ::::::
For first pick, you have 10 socks. (No need to find probability for this move, bcoz you have been told to pick two socks of same colour and not socks of a specific color).
Second move:: Now u have a sox of a color. U ve 9 socks remaining wid you. So, since dere are 5 pairs each of different color, and u ve picked one sox, so out of remaining 9 sox, dere's only 1 sox wic is of same color wic u ve picked. Thus desired event/total event = 1/9

Shekhar Agrawal said...

Hi..
What about Ques 6.
I am trying with Single and double differtiation method, but it's getting lengthy.
Is dere any direct method to find the product of maxima and minima

Shekhar Agrawal said...

Hi
For Ques 8.

If
(a^2 @ b^2) = a^2-b^2
(a^2 # b^2) = a^2+b^2

then
Col A: (2^2@-2^2) # (3^2@-3^2)
Col B: 0

Sol:::::::::
(2^2@-2^2) = (2^2 + 2^2) = 8
(3^2@-3^2) = (9 + 9) = 18
8#18 = 8+18 = 26 >0
so, answer shud be 'A'

Please correct me if I am wrong. Look the other 2 posts also

Lite said...

hi,
for 2nd question i guess as (s,t) are abscissa and ordinates of same point, while implementing the formula we get Col A and Col B equal

Shruthi said...

the ans for 9th
H.M = n/(1/x1+1/x2)
= 2/(1/10+1/20)
= 40/3

Anonymous said...

i think the answer for the 2nd question is D,as the point is not on the curve (s,t) cannot be determined
---please correct me if i am wrong

Anonymous said...

VICKY,

BRO.. PLZ UPDATE IT I HAVE MY EXAM ON 21 OF THIS MONTH.

PLZ PLA PLZ

Friday, September 12, 2008

12th september Gre Quants Question

1. If n is a odd positive integer, then
Col A: (-2)^((n+1)/2)
Col B: (-2)^((n-1)/2)

2.

Given equation of the parabola as y = 2x-x^2.
Col A: t
Col B: 2s-s^2

3. A person has 5 pairs of sox and each are differently colored. If a person picks one pair of sox simultaneously, what is the probability that it is of same colored pair?

4. How many different 5 digit numbers can formed, such that 1st and last place should be filled up with odd number.
A.25000
B.20000
so on….

5. If (4/7) = (4+s)/(7+t), then
Col A: s
Col B: (4t/7)

6. If x(x-15/7)(x+4)(x+3)=0, then what is the product of maximum and minimum value of x?

7. If a square of 125cm3 is fit into a cylinder, then what should be the minimum value of the volume of the cylinder?

8. If (a^2 @ b^2) = a^2-b^2 & (a^2 # b^2) = a^2+b^2, then
Col A: (2^2@-2^2) # (3^2@-3^2)
Col B: 0

9. The Harmonic Mean of 10, 20 is ………..

18 comments:

Anonymous said...

1.D
2.B
3.1/9
4.6720
5.C
6.-60/7
7.98.214
8.C
9.40/3

Please check the quant database for the diagram of the 2nd Question


Please correct me if iam wrong anywhere

Anonymous said...

hey can u explain how did u solve 7th question ??

Anonymous said...

Hi chirag,

for the 7th question.....square with 125cubic cm is cube.

For the cube to fit in the cylinder, the diameter of the cylinder should atleast be 5 and the height of the cylinder should atleast be 5

Therefore, r=2.5 and h=5

Minimum volume of a cylinder = pie * r^2*h
=3.14*(2.5^2)*5=98.214

Please correct me if iam wrong anywhere

Anonymous said...

Hi chirag,

i made a mistake

the diameter of the cylinder should atleast be the diagonal of the square

Diameter= 5(sqrt2)
radius=5/(sqrt2)

Volume=3.14*(25/2)*5 = 196.43

Please let me know in case of any Issues

Anonymous said...

can anyone explain me the second ques briefly...

i am obfuscated.....

Anonymous said...

Hi pradeey,

from the diagram,

y=2x-x^2 only at the apex of the parabola...for all the points inside the parabola,,,y will be less than 2x-x^2

Given point (s,t) is inside the parabola,
Therefore,t < 2s-s^2

Answer is B

Please let me know in case of any issues

Anonymous said...

if a cube is to fit into a cylinder, the min height of cylinder must be equal to height of cube=5
where as the radius of cylinder on top surface must be half of hypotenuse of square surface of cube, hypotenuse=5*sqrt(2)
r=5*sqrt(2)/2=7.07/2=3.535,
vol of cylinder=pie*r^2*h,=196.19

Anonymous said...

question no 4 answer is 25000

there are five places to b filled _ _ _ _ _

first and last places can b filled in five ways 5*5(ie 1,3,5,7,9)

second third and fourth places can be filled in 10 ways (0,1,2.....9)


therefore the answer is 5 * 10 * 10 * 10 * 5

=25000

Anonymous said...

pls explain 9 th question

Anonymous said...

Hi senthil,

for the 9th question

HM = 2/((1/a)+(1/b))

Use this formula,u vl get the answer

Please correct me if iam wrong

Ganta Pothuluri Reddy said...

please solve 3rd ?...i am confused

Shekhar Agrawal said...

Hi Ganta
For Ques 3rd

There are 5 pairs , i.e. 10 socks. You have picked 2.
Lets start solving ::::::
For first pick, you have 10 socks. (No need to find probability for this move, bcoz you have been told to pick two socks of same colour and not socks of a specific color).
Second move:: Now u have a sox of a color. U ve 9 socks remaining wid you. So, since dere are 5 pairs each of different color, and u ve picked one sox, so out of remaining 9 sox, dere's only 1 sox wic is of same color wic u ve picked. Thus desired event/total event = 1/9

Shekhar Agrawal said...

Hi..
What about Ques 6.
I am trying with Single and double differtiation method, but it's getting lengthy.
Is dere any direct method to find the product of maxima and minima

Shekhar Agrawal said...

Hi
For Ques 8.

If
(a^2 @ b^2) = a^2-b^2
(a^2 # b^2) = a^2+b^2

then
Col A: (2^2@-2^2) # (3^2@-3^2)
Col B: 0

Sol:::::::::
(2^2@-2^2) = (2^2 + 2^2) = 8
(3^2@-3^2) = (9 + 9) = 18
8#18 = 8+18 = 26 >0
so, answer shud be 'A'

Please correct me if I am wrong. Look the other 2 posts also

Lite said...

hi,
for 2nd question i guess as (s,t) are abscissa and ordinates of same point, while implementing the formula we get Col A and Col B equal

Shruthi said...

the ans for 9th
H.M = n/(1/x1+1/x2)
= 2/(1/10+1/20)
= 40/3

Anonymous said...

i think the answer for the 2nd question is D,as the point is not on the curve (s,t) cannot be determined
---please correct me if i am wrong

Anonymous said...

VICKY,

BRO.. PLZ UPDATE IT I HAVE MY EXAM ON 21 OF THIS MONTH.

PLZ PLA PLZ