Tuesday, September 9, 2008

9th September GRE Quants Que

1. A circle with centre 'O' has a diameter d. If AB is any chord, then
Col A: perimeter of triangle OAB
Col B: 5d/3

2. If x and y are positive even numbers, then
Col A: (-1)^(x+y)/2
Col B: (-1)^(x+y)

3. How many distinct five digit numbers are there... that begin and end with odd numbers?

4. Given a figure of rectangle with base 15 and height 12, reduce one of the heights to 8 units... now join the shorter height to the longer height.. like a staircase with different heights at each step... the question was to find the length of the staircase?
(Question is similar to this)

5. Col A: 199!/198!
Col B: (199!-198!)/197!

6 A person has 10 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?
A. 1/5
B. 1/10
C. 1/9
D. 2/9
E. xxx(some value)

7. There is a parabola whose equation is y = 2x - x^2. The parabola was drawn such that, the curvy part was in the first quadrant... now (s, t) is any point between positive x-axis and the curve.
Col A: t
Col B: 2s-s^2

8. Mary buys a product at 80% of its value, she buys another product at 70% of its value. If two products are brought together
Col A: What is the total percent of discount
Col B: 75%

9. One bucket with a capacity of V was 1/3rd full.. & another bucket with a capacity of W was 1/4th full. With the same liquid..now, if the two are emptied into another bucket with capacity of x, what fraction of x is full?
(Question is similar to this)

10. If a clock shows exactly 4 '0' clock right now, then what will it show exactly 1195 hours later?

11. Given a sequence a1, a2........ an. If a1 = 25 & in the sequence if every number is '-2' times the preceding number, then
Col A: a100
Col B: -10,000

12. If 'f' is function such that f(x) = sum of prime factors of x (even repeating prime factors)
Col A: f(256)
Col B: f(210)

13. If f(n) = (n(n+1))/2 and 'm' is an integer >0 then
Col A: (-1)^f(m+1)
Col B: (-1)^f(m+2)

14. 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 a same colored pair?

15. If x(x+4)(2x-15)(x+3) = 0, then find the product of the least value and the greatest value of x?

16. The probability of A hitting the target is 2/3. And probability of B hitting the same target is 4/7. So, what is the probability that neither of them will hit the target?

try to answer them as soon as possible....

12 comments:

Anonymous said...

The answers are :
1.D
2.C
3.15120
4.?
5.B
6.1/19
7.?
8.?
9.(3W+4V)/12x
10.11AM
11.B
12.B
13.C
14.1/9
15.-30
16.1/7

Please correct me if iam wrong anywhere

Anonymous said...

I think in 2 ques Ans is D...

If we select x=2 & y=2 then quantities are equal

If we select x=2 & y=4 then Bis Greater so I think D will be the ans..Pls reply///

Anonymous said...

Hi ravi,

In 2nd question, we asked to find whether the value of (-1) is equal in both the cases.According to me.(x+y) and (x+y)/2 depicts the same kind of value(either odd or even).So watever the values x and y are COl A: and COlB will be equal.

Please correct me if iam wrong

Anonymous said...

the answer what i gave is wrong..i dint read the question properly

here's the answer...the 1st digit and the last digit can be filled in 5 and 4 ways respectively(as per the given condition).the 2nd, 3rd and 4th digits of the number can be filled in 8,7,6 ways(as distinct 5 digit numbers are required).

Therefore the answer is 5*8*7*6*4=6720

The answer for th 8th question D

Please let me know in case of any Issues

Anonymous said...

For the 15th one, the values we get for x are 0,-3,-4, and 15/2.

We require the product of the least and the greates value of x.

least value=-4
greatest value=15/2

the product is -30.

Please correct me if iam wrong


for the 13th one,

f(m+1)=(m+1)(m+2)/2
=(m^2+3m+2)/2

f(m+2)=(m+2)(m+3)/2
=(m^2+5m+6)/2

Given m>0 and m is an integer,
put m=1,f(m+1)=6,f(m+2)=12
put m=2,f(m+1)=12,f(m+2)=20

for watever value we give for m,f(m+1) and f(m+2) will be even

so (-1)^f(m+1) will be equal to (-1)^f(m+2)

Please correct me if iam wrong

Anonymous said...

for the 13th one,

f(m+1)=(m+1)(m+2)/2
=(m^2+3m+2)/2

f(m+2)=(m+2)(m+3)/2
=(m^2+5m+6)/2

Given m>0 and m is an integer,
put m=1,f(m+1)=6,f(m+2)=12

SEE UR WRONG HERE...
m=1 we get
f(m+1)= 3
f(m+2)=6;
u forgot to div i guess

[/b]

Anonymous said...

hello

answer for parabola quest....


given equation is y= 2x - x^2

write it as (x^2 -2x +1)= -y+1

therefore (x-1)^2 = -(y-1)

origin of parabola is shifted to (1,1) and the parabola passes thru (0,0) and (2,0)
max value of x is 2 and y is 1

given point (s,t) is between +ve x axis and curve.... for all points between x axis and curve .....y < 2x - x^2

therefore t < 2s - s^2
so answer is B

correct me if i'm wrong

Anonymous said...

Hi,

the 12th Question..
256=2^8...therefore, the sum of prime factors =16
210=(3*5*7*2)=3+5+7+2=17

Therefore,COLB is greater.Therefore,B is the answer

the 14th question,5C1/10C2=1/9

Please let me know in case of any Issues

Anonymous said...

Hi Ganesh

Denominator

There 10 socks and we have to pick 2 socks simultaneously...so number of ways of picking the socks = 10C2

Numerator

The 2 socks picked by you should be of same colour.There are 5 pairs of socks which are of different colour.
In order to pick 2 socks of same colour, we have to pick 1 pair of socks from the 5 pairs

So, numerator= 5C1

Therefore, answer= 5C1/10C2

Please correct me if iam wrong

Anonymous said...

16. The probability of A hitting the target is 2/3. And probability of B hitting the same target is 4/7. So, what is the probability that neither of them will hit the target?

ANS) we need to find [P(A П B)] ' = 1 - P(AПB) = 1- [P(A)P(B)]

= 1- ((2/3)*(4/7)) = 1 - (8/21) = 13/21

so the ans is 13/21 for the 16th question


it's wrong to interpret [P(A П B)] ' as [P(A)' * P(B)']

Anonymous said...

@ venki

hey , how can u solve 3rd question....please explain...

Unknown said...

ganesh YOU ARE WRONG!

one of them will hit the target:
P(A or B) = P(A) + P (B) - P(A)*P(B)

none of them will hit the target:
1 - P(A or B)


It is not wrong to interpret the same answer as (1-P(A))*(1-P(A)) as the two events are independent. You get the same answer.

But your answer 13/21 doesn't even make sense, its TOO HIGH (0.6) compared to the each persons probability of hitting the target (>0.5)

Tuesday, September 9, 2008

9th September GRE Quants Que

1. A circle with centre 'O' has a diameter d. If AB is any chord, then
Col A: perimeter of triangle OAB
Col B: 5d/3

2. If x and y are positive even numbers, then
Col A: (-1)^(x+y)/2
Col B: (-1)^(x+y)

3. How many distinct five digit numbers are there... that begin and end with odd numbers?

4. Given a figure of rectangle with base 15 and height 12, reduce one of the heights to 8 units... now join the shorter height to the longer height.. like a staircase with different heights at each step... the question was to find the length of the staircase?
(Question is similar to this)

5. Col A: 199!/198!
Col B: (199!-198!)/197!

6 A person has 10 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?
A. 1/5
B. 1/10
C. 1/9
D. 2/9
E. xxx(some value)

7. There is a parabola whose equation is y = 2x - x^2. The parabola was drawn such that, the curvy part was in the first quadrant... now (s, t) is any point between positive x-axis and the curve.
Col A: t
Col B: 2s-s^2

8. Mary buys a product at 80% of its value, she buys another product at 70% of its value. If two products are brought together
Col A: What is the total percent of discount
Col B: 75%

9. One bucket with a capacity of V was 1/3rd full.. & another bucket with a capacity of W was 1/4th full. With the same liquid..now, if the two are emptied into another bucket with capacity of x, what fraction of x is full?
(Question is similar to this)

10. If a clock shows exactly 4 '0' clock right now, then what will it show exactly 1195 hours later?

11. Given a sequence a1, a2........ an. If a1 = 25 & in the sequence if every number is '-2' times the preceding number, then
Col A: a100
Col B: -10,000

12. If 'f' is function such that f(x) = sum of prime factors of x (even repeating prime factors)
Col A: f(256)
Col B: f(210)

13. If f(n) = (n(n+1))/2 and 'm' is an integer >0 then
Col A: (-1)^f(m+1)
Col B: (-1)^f(m+2)

14. 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 a same colored pair?

15. If x(x+4)(2x-15)(x+3) = 0, then find the product of the least value and the greatest value of x?

16. The probability of A hitting the target is 2/3. And probability of B hitting the same target is 4/7. So, what is the probability that neither of them will hit the target?

try to answer them as soon as possible....

12 comments:

Anonymous said...

The answers are :
1.D
2.C
3.15120
4.?
5.B
6.1/19
7.?
8.?
9.(3W+4V)/12x
10.11AM
11.B
12.B
13.C
14.1/9
15.-30
16.1/7

Please correct me if iam wrong anywhere

Anonymous said...

I think in 2 ques Ans is D...

If we select x=2 & y=2 then quantities are equal

If we select x=2 & y=4 then Bis Greater so I think D will be the ans..Pls reply///

Anonymous said...

Hi ravi,

In 2nd question, we asked to find whether the value of (-1) is equal in both the cases.According to me.(x+y) and (x+y)/2 depicts the same kind of value(either odd or even).So watever the values x and y are COl A: and COlB will be equal.

Please correct me if iam wrong

Anonymous said...

the answer what i gave is wrong..i dint read the question properly

here's the answer...the 1st digit and the last digit can be filled in 5 and 4 ways respectively(as per the given condition).the 2nd, 3rd and 4th digits of the number can be filled in 8,7,6 ways(as distinct 5 digit numbers are required).

Therefore the answer is 5*8*7*6*4=6720

The answer for th 8th question D

Please let me know in case of any Issues

Anonymous said...

For the 15th one, the values we get for x are 0,-3,-4, and 15/2.

We require the product of the least and the greates value of x.

least value=-4
greatest value=15/2

the product is -30.

Please correct me if iam wrong


for the 13th one,

f(m+1)=(m+1)(m+2)/2
=(m^2+3m+2)/2

f(m+2)=(m+2)(m+3)/2
=(m^2+5m+6)/2

Given m>0 and m is an integer,
put m=1,f(m+1)=6,f(m+2)=12
put m=2,f(m+1)=12,f(m+2)=20

for watever value we give for m,f(m+1) and f(m+2) will be even

so (-1)^f(m+1) will be equal to (-1)^f(m+2)

Please correct me if iam wrong

Anonymous said...

for the 13th one,

f(m+1)=(m+1)(m+2)/2
=(m^2+3m+2)/2

f(m+2)=(m+2)(m+3)/2
=(m^2+5m+6)/2

Given m>0 and m is an integer,
put m=1,f(m+1)=6,f(m+2)=12

SEE UR WRONG HERE...
m=1 we get
f(m+1)= 3
f(m+2)=6;
u forgot to div i guess

[/b]

Anonymous said...

hello

answer for parabola quest....


given equation is y= 2x - x^2

write it as (x^2 -2x +1)= -y+1

therefore (x-1)^2 = -(y-1)

origin of parabola is shifted to (1,1) and the parabola passes thru (0,0) and (2,0)
max value of x is 2 and y is 1

given point (s,t) is between +ve x axis and curve.... for all points between x axis and curve .....y < 2x - x^2

therefore t < 2s - s^2
so answer is B

correct me if i'm wrong

Anonymous said...

Hi,

the 12th Question..
256=2^8...therefore, the sum of prime factors =16
210=(3*5*7*2)=3+5+7+2=17

Therefore,COLB is greater.Therefore,B is the answer

the 14th question,5C1/10C2=1/9

Please let me know in case of any Issues

Anonymous said...

Hi Ganesh

Denominator

There 10 socks and we have to pick 2 socks simultaneously...so number of ways of picking the socks = 10C2

Numerator

The 2 socks picked by you should be of same colour.There are 5 pairs of socks which are of different colour.
In order to pick 2 socks of same colour, we have to pick 1 pair of socks from the 5 pairs

So, numerator= 5C1

Therefore, answer= 5C1/10C2

Please correct me if iam wrong

Anonymous said...

16. The probability of A hitting the target is 2/3. And probability of B hitting the same target is 4/7. So, what is the probability that neither of them will hit the target?

ANS) we need to find [P(A П B)] ' = 1 - P(AПB) = 1- [P(A)P(B)]

= 1- ((2/3)*(4/7)) = 1 - (8/21) = 13/21

so the ans is 13/21 for the 16th question


it's wrong to interpret [P(A П B)] ' as [P(A)' * P(B)']

Anonymous said...

@ venki

hey , how can u solve 3rd question....please explain...

Unknown said...

ganesh YOU ARE WRONG!

one of them will hit the target:
P(A or B) = P(A) + P (B) - P(A)*P(B)

none of them will hit the target:
1 - P(A or B)


It is not wrong to interpret the same answer as (1-P(A))*(1-P(A)) as the two events are independent. You get the same answer.

But your answer 13/21 doesn't even make sense, its TOO HIGH (0.6) compared to the each persons probability of hitting the target (>0.5)