Tuesday, September 16, 2008

16 september Gre Quants Question

1.

Given a figure of 18 eighteen equilateral triangles as above with each side length of 1. What is the perimeter of the figure?

2. If 8 < 2x < 14 and 6 < x+3 < 9, then
Col A: x
Col B: 5

3. Given a right angled cylinder of diameter 20feet and height 4feet. What is the volume of the cylinder in gallons, when up to a depth of 3 feet and 6 inches? (Hint: 1 foot = 12 inches; 1 gallon = 231cubic.inches)

4. Given a set of numbers as 15, 16, 17, 18 & 19 and another set of numbers were given as 8, 9, 10, 11, 12, 13 & 14. When the two sets were added, how many such different numbers were possible?

5.

If the radius of the given circle is 5units, then how many points lie on the circle?
A. 8
B. 10
C. 12
D. 16
E. 20

6. If ‘X’ invests Rs.5000 at the rate of 6% for annual and ‘Y’ invests Rs.6000 at the rate 6% for semiannual, then
Col A: The interest ‘X’ gets for 1year
Col B: The interest ‘Y’ gets for 1year

7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

8. Given that ‘r’ is a three digit number such that it contains ‘x’ in its hundredth place, ‘y’ in tens place, ‘z’ in units place. If’ x’ is multiplied by 9, ‘y’ is multiplied by 6 and ‘z’ is multiplied by 2 then what is the value of the N735 (here 735 is given as suffix, & Question mean that r=735)
A. 72
B. 79
C. 86
D. 91
E. & so on…
Ans: D

9. If x < 0 then
Col A: -x
Col B: lxl

10. If the point (2,3) lies on the line mx + ky = 1
Col A: k
Col B: 0

11.

Given equation of the line as x + y – 4 = 0
Col A: Length of OB
Col B: Length of OC

12. If (n-2)(n-3) = 0, then
Col A: -2n-1
Col B: 2n-1

13. 1^-3 + 2^-2 + 3^-1 =?

14. Set A: 10, 30, 50, 70 & 90
Set B: 10, 20, 50, 80 & 90
Col A: standard deviation of A
Col B: standard deviation of B

15. If x, y, z are integers
Col A: yz/x
Col B: y/xz

16. If ak = 1/k – 1/(k+1), then find the summation of a1 to a100?

20 comments:

Anonymous said...

1)12
2)D
3)?
4)11
5)?
6)B
7)?
8)91
9)C
10)D
11)C
12)B
13)-(5/12)
14)C
15)D
16)?

Anonymous said...

sorry
answer for fourth question is


4)11

Anonymous said...

answer for


6)A

Anonymous said...

Explanation of the problems

1. It's evident that the permeter will be 4+4+2+2=12

2. If 8 < 2x < 14 and 6 < x+3 < 9, then
Col A: x
Col B: 5
Answer will be cannot be defined. Take x=5 it satisifies the givn relation. Take x=4.5 it also satisifies the given relationship

3. Given a right angled cylinder of diameter 20feet and height 4feet. What is the volume of the cylinder in gallons, when up to a depth of 3 feet and 6 inches? (Hint: 1 foot = 12 inches; 1 gallon = 231cubic.inches)

The question seems unclear I think the second line should read "when full up to a depth of 3 feet and 6 inches".
Volume of the cylinder when filled upto 3ft6in is
Pi(20*20)/4+3.5 (As 6 inch is half foot)
=Pi*100+3.5
=344.5Cube ft

1 foot = 12 inches
1 Cube foot = 12^3 cube inches
344.5Cube ft=344.5*12^3 cube inches

231cubic.inches=1 Gallon
344.5*12^3 cube inches=344.5*12^3/231 Gallon =2560 Gallons(Approx) 2577.03896104 (Actual)

4. Given a set of numbers as 15, 16, 17, 18 & 19 and another set of numbers were given as 8, 9, 10, 11, 12, 13 & 14. When the two sets were added, how many such different numbers were possible?

The fastest way to do the problem without adding up numbers and listing them is as the numbers are consecutive the number of unique numbers by adding them together is
Number of element of list1 + Number of element in list2 - 1.
This is only applicable when the numbers in both the list are consecutive or are in AP with a common d.
So answer is 7+5-1=11

5. If the radius of the given circle is 5units, then how many points lie on the circle?
A. 8
B. 10
C. 12
D. 16
E. 20

I think there is a problem with the question. As we know there are infinite number of points on any locus of a point.

Anonymous said...

6. If ‘X’ invests Rs.5000 at the rate of 6% for annual and ‘Y’ invests Rs.6000 at the rate 6% for semiannual, then
Col A: The interest ‘X’ gets for 1year
Col B: The interest ‘Y’ gets for 1year

Answer will be Col A will be greater.

7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

The best way to answer the question is using back substitution. Find the third side length from the given option by subtracting 20 from it then find the height by using pythagorous theorm and then calculate the area. height^2=100-(side/2)^2 If it is 32 then you got the answer. Start from C.

9. If x < 0 then
Col A: -x
Col B: lxl

Both are equal

10. If the point (2,3) lies on the line mx + ky = 1
Col A: k
Col B: 0

Cannot be defined. as we have one equatin and two unknowns. m and k

11. Given equation of the line as x + y - 4 = 0
Col A: Length of OB
Col B: Length of OC
Both will be equal. As the lines cuts the X-axes at (4,0) and yaxes at (0,4). Just put y=0 and find x and x=0 and find y.

12. If (n-2)(n-3) = 0, then
Col A: -2n-1
Col B: 2n-1

Col B wil be greater as Col A is always -ve and Col B is always +ve

13. 1^-3 + 2^-2 + 3^-1
1+1/4+1/3
1+ 7/12
=19/12


14. Set A: 10, 30, 50, 70 & 90
Set B: 10, 20, 50, 80 & 90
Col A: standard deviation of A
Col B: standard deviation of B

Col B will be greater. This can also be done without doing calculations. It is evident that both have mean value 50. now in Set A all elements differ from 50 by 40,20,0,20,40 respectively and in set B they differ as 40,30,0,30,40. As the standard deviation measure how much the data deviates from the mean value it is evedent that there is more deviation is Set B as compared to Set A. So Col B will be greater.


15. If x, y, z are integers
Col A: yz/x
Col B: y/xz

Since no conditions/constraint is given it is Undefined.

16. If ak = 1/k - 1/(k+1), then find the summation of a1 to a100?

a1=1-1/2
a1+a2=1-1/2+1/2-1/3=1-1/3
a1+a2+a3=1-1/3+1/3-1/4=1-1/4
a1+....+an=1-1/n+1
a1+....+a100=1-1/101=100/101

Anonymous said...
This comment has been removed by a blog administrator.
Anonymous said...

What is the meaning of the Question No 8. and how do u get 91 as answer?Can you please explain?

Anonymous said...

7*9=63
+
3*6=18
+
5*2=10

63+18+10=91 Smile

let me know if i am wrong.....

Anonymous said...

You are right. Actually I was not able to understand the question. That's why I asked.

Anonymous said...

In q. 9

If x < 0 then
Col A: -x
Col B: lxl = -x only as its given in questn that x is -ve
So ans shd be C..!!

Please correct me if m wrong..!

Anonymous said...

No you are not wrong. By definition
lxl = x when x>0 and -x when x<0
and as it is given in the question x<0 lxl=-x
So you are absolutely correct.

Anonymous said...

8. Given that ‘r’ is a three digit number such that it contains ‘x’ in its hundredth place, ‘y’ in tens place, ‘z’ in units place. If’ x’ is multiplied by 9, ‘y’ is multiplied by 6 and ‘z’ is multiplied by 2 then what is the value of the N735 (here 735 is given as suffix, & Question mean that r=735)
A. 72
B. 79
C. 86
D. 91
E. & so on…
Ans: D


hey pradeey, i dint really understand the logic of the question .... tho the soln is fine.

we havnt used the info tht r= 100x+10y+z, N 735 ..... is tht some standard notation....???

kindly xplain

Anonymous said...

according to the given statement 'r' is 'xyz' which is nothing but '735' ...so u have to find the value of N suffix 735 by applying the condition.

nothing to get obfuscated....

Anonymous said...

I found a solution for Q7
7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

It is evident from the question that it is an Isosceles triangle. So the height of the triangle will divide the total triangle into regions of two equal area. Here I am talking about the height drawn on the unequal side from the point of intersection of equal side.

Now consider half of the triangle. Area will be 16. It will be a Right Angles triangle with h=10. Now 'p' will be the height and 'b' is half of the length of third side.

So we have two equations

p^2 + b^2=10^2
p^2 + b^2=100---------------1

0.5*p*b=16
2*p*b=64-------------------2

(p+b)^2 = 100+64=164
p+b=12.8(Approx as 13^2 = 169)--------------3

now
(p-b)^2 = 100-64=36
p-b=6----------------------------------------4

Now solving equn 3 and 4 we get

p=18.8/2 = 9.4
b= 3.4

Now since 'b' is half of the length of third side. third side length will be 3.4 *2 = 6.8 = 7(Nearest Approximation)

So perimeter of the triangle will be 10+10+7=27

PS- When i woke up up the morning i had this idea in my mind. Don't know how I manage to solve it while sleeping.

Anonymous said...

hey


have u ever thought what would happen to ur equation 4 if it is taken as (b-p)^2

u would finally arrive at the answer

b=9.8
p=3.4

Anonymous said...

1.

Given a figure of 18 eighteen equilateral triangles as above with each side length of 1. What is the perimeter of the figure?

hw to solve this??? i dint get hws itt 12

Anonymous said...

hey dont be pedantic with the question....


perimeter is simply the sum of all the sides of the figure..


now closely watch the figure there are 4 triangles with its base on both side and two triangles with its side on the other two sides.

since the triangle has side 1 (given )

Perimeter = 4+4+2+2=12

let me know if u cant still get it.

Anonymous said...

can someone clarify question 6?
how col A be greater?

Shekhar Agrawal said...

Hi Jitun..
Q 5 is absolutely rite.... it is asking to find the integral points on the circle.

Solution: (@ = theta)

Circle equation: (rCos@ - rSin@). Since radius is 5, the equation becomes (5Cos@ - 5Sin@). To have integral points 5Cos@ and 5Sin@ shud be an integer and not irrational.
For 5Cos@ to be an integer, the values of Cos@ may be {1/5 , 2/5 , 3/5 , 4/5, 5/5}
Now you have to find what can be the value of Sin@ at each point. First two values are not possible for sin@. Next 3 are possible.
For that vertices (3,4) , (4,3) , (5,0) are the values..
Now consider these 3 values.. first two will have 4 values each in 4 quadrants and last one will have just two on x and y axis.
MAKING A TOTAL OF 10.
ANS:::10

But i beleive dese types of questions will not be asked by us...
Cheers

Anonymous said...

manoj rana
sep 16th
5)12 for sure

Tuesday, September 16, 2008

16 september Gre Quants Question

1.

Given a figure of 18 eighteen equilateral triangles as above with each side length of 1. What is the perimeter of the figure?

2. If 8 < 2x < 14 and 6 < x+3 < 9, then
Col A: x
Col B: 5

3. Given a right angled cylinder of diameter 20feet and height 4feet. What is the volume of the cylinder in gallons, when up to a depth of 3 feet and 6 inches? (Hint: 1 foot = 12 inches; 1 gallon = 231cubic.inches)

4. Given a set of numbers as 15, 16, 17, 18 & 19 and another set of numbers were given as 8, 9, 10, 11, 12, 13 & 14. When the two sets were added, how many such different numbers were possible?

5.

If the radius of the given circle is 5units, then how many points lie on the circle?
A. 8
B. 10
C. 12
D. 16
E. 20

6. If ‘X’ invests Rs.5000 at the rate of 6% for annual and ‘Y’ invests Rs.6000 at the rate 6% for semiannual, then
Col A: The interest ‘X’ gets for 1year
Col B: The interest ‘Y’ gets for 1year

7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

8. Given that ‘r’ is a three digit number such that it contains ‘x’ in its hundredth place, ‘y’ in tens place, ‘z’ in units place. If’ x’ is multiplied by 9, ‘y’ is multiplied by 6 and ‘z’ is multiplied by 2 then what is the value of the N735 (here 735 is given as suffix, & Question mean that r=735)
A. 72
B. 79
C. 86
D. 91
E. & so on…
Ans: D

9. If x < 0 then
Col A: -x
Col B: lxl

10. If the point (2,3) lies on the line mx + ky = 1
Col A: k
Col B: 0

11.

Given equation of the line as x + y – 4 = 0
Col A: Length of OB
Col B: Length of OC

12. If (n-2)(n-3) = 0, then
Col A: -2n-1
Col B: 2n-1

13. 1^-3 + 2^-2 + 3^-1 =?

14. Set A: 10, 30, 50, 70 & 90
Set B: 10, 20, 50, 80 & 90
Col A: standard deviation of A
Col B: standard deviation of B

15. If x, y, z are integers
Col A: yz/x
Col B: y/xz

16. If ak = 1/k – 1/(k+1), then find the summation of a1 to a100?

20 comments:

Anonymous said...

1)12
2)D
3)?
4)11
5)?
6)B
7)?
8)91
9)C
10)D
11)C
12)B
13)-(5/12)
14)C
15)D
16)?

Anonymous said...

sorry
answer for fourth question is


4)11

Anonymous said...

answer for


6)A

Anonymous said...

Explanation of the problems

1. It's evident that the permeter will be 4+4+2+2=12

2. If 8 < 2x < 14 and 6 < x+3 < 9, then
Col A: x
Col B: 5
Answer will be cannot be defined. Take x=5 it satisifies the givn relation. Take x=4.5 it also satisifies the given relationship

3. Given a right angled cylinder of diameter 20feet and height 4feet. What is the volume of the cylinder in gallons, when up to a depth of 3 feet and 6 inches? (Hint: 1 foot = 12 inches; 1 gallon = 231cubic.inches)

The question seems unclear I think the second line should read "when full up to a depth of 3 feet and 6 inches".
Volume of the cylinder when filled upto 3ft6in is
Pi(20*20)/4+3.5 (As 6 inch is half foot)
=Pi*100+3.5
=344.5Cube ft

1 foot = 12 inches
1 Cube foot = 12^3 cube inches
344.5Cube ft=344.5*12^3 cube inches

231cubic.inches=1 Gallon
344.5*12^3 cube inches=344.5*12^3/231 Gallon =2560 Gallons(Approx) 2577.03896104 (Actual)

4. Given a set of numbers as 15, 16, 17, 18 & 19 and another set of numbers were given as 8, 9, 10, 11, 12, 13 & 14. When the two sets were added, how many such different numbers were possible?

The fastest way to do the problem without adding up numbers and listing them is as the numbers are consecutive the number of unique numbers by adding them together is
Number of element of list1 + Number of element in list2 - 1.
This is only applicable when the numbers in both the list are consecutive or are in AP with a common d.
So answer is 7+5-1=11

5. If the radius of the given circle is 5units, then how many points lie on the circle?
A. 8
B. 10
C. 12
D. 16
E. 20

I think there is a problem with the question. As we know there are infinite number of points on any locus of a point.

Anonymous said...

6. If ‘X’ invests Rs.5000 at the rate of 6% for annual and ‘Y’ invests Rs.6000 at the rate 6% for semiannual, then
Col A: The interest ‘X’ gets for 1year
Col B: The interest ‘Y’ gets for 1year

Answer will be Col A will be greater.

7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

The best way to answer the question is using back substitution. Find the third side length from the given option by subtracting 20 from it then find the height by using pythagorous theorm and then calculate the area. height^2=100-(side/2)^2 If it is 32 then you got the answer. Start from C.

9. If x < 0 then
Col A: -x
Col B: lxl

Both are equal

10. If the point (2,3) lies on the line mx + ky = 1
Col A: k
Col B: 0

Cannot be defined. as we have one equatin and two unknowns. m and k

11. Given equation of the line as x + y - 4 = 0
Col A: Length of OB
Col B: Length of OC
Both will be equal. As the lines cuts the X-axes at (4,0) and yaxes at (0,4). Just put y=0 and find x and x=0 and find y.

12. If (n-2)(n-3) = 0, then
Col A: -2n-1
Col B: 2n-1

Col B wil be greater as Col A is always -ve and Col B is always +ve

13. 1^-3 + 2^-2 + 3^-1
1+1/4+1/3
1+ 7/12
=19/12


14. Set A: 10, 30, 50, 70 & 90
Set B: 10, 20, 50, 80 & 90
Col A: standard deviation of A
Col B: standard deviation of B

Col B will be greater. This can also be done without doing calculations. It is evident that both have mean value 50. now in Set A all elements differ from 50 by 40,20,0,20,40 respectively and in set B they differ as 40,30,0,30,40. As the standard deviation measure how much the data deviates from the mean value it is evedent that there is more deviation is Set B as compared to Set A. So Col B will be greater.


15. If x, y, z are integers
Col A: yz/x
Col B: y/xz

Since no conditions/constraint is given it is Undefined.

16. If ak = 1/k - 1/(k+1), then find the summation of a1 to a100?

a1=1-1/2
a1+a2=1-1/2+1/2-1/3=1-1/3
a1+a2+a3=1-1/3+1/3-1/4=1-1/4
a1+....+an=1-1/n+1
a1+....+a100=1-1/101=100/101

Anonymous said...
This comment has been removed by a blog administrator.
Anonymous said...

What is the meaning of the Question No 8. and how do u get 91 as answer?Can you please explain?

Anonymous said...

7*9=63
+
3*6=18
+
5*2=10

63+18+10=91 Smile

let me know if i am wrong.....

Anonymous said...

You are right. Actually I was not able to understand the question. That's why I asked.

Anonymous said...

In q. 9

If x < 0 then
Col A: -x
Col B: lxl = -x only as its given in questn that x is -ve
So ans shd be C..!!

Please correct me if m wrong..!

Anonymous said...

No you are not wrong. By definition
lxl = x when x>0 and -x when x<0
and as it is given in the question x<0 lxl=-x
So you are absolutely correct.

Anonymous said...

8. Given that ‘r’ is a three digit number such that it contains ‘x’ in its hundredth place, ‘y’ in tens place, ‘z’ in units place. If’ x’ is multiplied by 9, ‘y’ is multiplied by 6 and ‘z’ is multiplied by 2 then what is the value of the N735 (here 735 is given as suffix, & Question mean that r=735)
A. 72
B. 79
C. 86
D. 91
E. & so on…
Ans: D


hey pradeey, i dint really understand the logic of the question .... tho the soln is fine.

we havnt used the info tht r= 100x+10y+z, N 735 ..... is tht some standard notation....???

kindly xplain

Anonymous said...

according to the given statement 'r' is 'xyz' which is nothing but '735' ...so u have to find the value of N suffix 735 by applying the condition.

nothing to get obfuscated....

Anonymous said...

I found a solution for Q7
7. Given a triangle with sides 10, 10 and the area of the triangle is given as 32. Find the perimeter of the triangle?

It is evident from the question that it is an Isosceles triangle. So the height of the triangle will divide the total triangle into regions of two equal area. Here I am talking about the height drawn on the unequal side from the point of intersection of equal side.

Now consider half of the triangle. Area will be 16. It will be a Right Angles triangle with h=10. Now 'p' will be the height and 'b' is half of the length of third side.

So we have two equations

p^2 + b^2=10^2
p^2 + b^2=100---------------1

0.5*p*b=16
2*p*b=64-------------------2

(p+b)^2 = 100+64=164
p+b=12.8(Approx as 13^2 = 169)--------------3

now
(p-b)^2 = 100-64=36
p-b=6----------------------------------------4

Now solving equn 3 and 4 we get

p=18.8/2 = 9.4
b= 3.4

Now since 'b' is half of the length of third side. third side length will be 3.4 *2 = 6.8 = 7(Nearest Approximation)

So perimeter of the triangle will be 10+10+7=27

PS- When i woke up up the morning i had this idea in my mind. Don't know how I manage to solve it while sleeping.

Anonymous said...

hey


have u ever thought what would happen to ur equation 4 if it is taken as (b-p)^2

u would finally arrive at the answer

b=9.8
p=3.4

Anonymous said...

1.

Given a figure of 18 eighteen equilateral triangles as above with each side length of 1. What is the perimeter of the figure?

hw to solve this??? i dint get hws itt 12

Anonymous said...

hey dont be pedantic with the question....


perimeter is simply the sum of all the sides of the figure..


now closely watch the figure there are 4 triangles with its base on both side and two triangles with its side on the other two sides.

since the triangle has side 1 (given )

Perimeter = 4+4+2+2=12

let me know if u cant still get it.

Anonymous said...

can someone clarify question 6?
how col A be greater?

Shekhar Agrawal said...

Hi Jitun..
Q 5 is absolutely rite.... it is asking to find the integral points on the circle.

Solution: (@ = theta)

Circle equation: (rCos@ - rSin@). Since radius is 5, the equation becomes (5Cos@ - 5Sin@). To have integral points 5Cos@ and 5Sin@ shud be an integer and not irrational.
For 5Cos@ to be an integer, the values of Cos@ may be {1/5 , 2/5 , 3/5 , 4/5, 5/5}
Now you have to find what can be the value of Sin@ at each point. First two values are not possible for sin@. Next 3 are possible.
For that vertices (3,4) , (4,3) , (5,0) are the values..
Now consider these 3 values.. first two will have 4 values each in 4 quadrants and last one will have just two on x and y axis.
MAKING A TOTAL OF 10.
ANS:::10

But i beleive dese types of questions will not be asked by us...
Cheers

Anonymous said...

manoj rana
sep 16th
5)12 for sure