GMAT Problem Solving Discussions

MBA
4166
Hi Tej,
I am sorry for late reply as I was not strolling through this section for long.
I have very nice book from veritas...its for Prob, Permu, Comb.

once u do this book i am sure u will be able to solve 80-90% of the problems.
i have the soft copy...
PM ur email id to me...I will send it to u asap.

silverline

Hi Silverline

My email id is [email protected], appreciate your help.

Rgds
Tej
4167
Hi Silverline

My email id is [email protected], appreciate your help.

Rgds
Tej


Hi Tej,
Sharing your personal information like e-mail addresses etc. are prohibited on PG. You can use personal messages for the same. You can refer to the following post for the same Rules/Guidelines at PaGaLGuY .

Anuj
4168

@Anuj

You got the answer for the above problem.
But I think the analysis should be something like this:

1)Case 1 R>0

When you consider R>0 , the solution can not be R =0.The solution has to be a value R>0.

I think this case gives no solution.

2)Case 2 R
Same.You eliminate 0 and +1 because we stipulated R
And we need to consider a third case , where R=0 which will satisfy the equation.

So we get two solutions
R=-1 from case 2 and R = 0 from case 3.

Your take?

Regards

4169

Hi, I need help with the following questions. Will appreciate if you can explain the method as well.

Q1) Last month 15 homes were sold in town X. The average sale price of the homes was $150,000 and the median sale price was $130,000. Which of the following must be true?

a) at least one of the homes was sold for more than $165,000.

b) at least one of the homes was sold for more than $130,000 and less than $150,000.

c) at least one of the homes was sold for less than $130,000.


Q2) A certain city with a population of 132,000 is to be divided into 11 districts and no district is to have a population that is more than 10% greater than the population of any other district. What is the minimum possible population that the least populated district could have?

a)10,000 b)10,800 c)11,000 d)11,500 e)12,000

Q3) Each employee of company Z is an employee of either division X or Y. If each division has some part time employees, is the ratio of no. of full time employees to the no. of part time employees greater for division X than for company Z? (data sufficiency)

1) The ratio of the number of full time employees to the number of part time employees is less for division Y than for company Z.

2) More than half of the full time employees of company Z are employees of division X, and more than half of the part time employees of company Z are employees of division Y.

Much thanks in advance. Also, I am looking for material on Mean, Median, Mode topic and Combination and Probability. Can any of you share?

4170
@Anuj

You got the answer for the above problem.
But I think the analysis should be something like this:

1)Case 1 R>0

When you consider R>0 , the solution can not be R =0.The solution has to be a value R>0.

I think this case gives no solution.

2)Case 2 R
Same.You eliminate 0 and +1 because we stipulated R
And we need to consider a third case , where R=0 which will satisfy the equation.

So we get two solutions
R=-1 from case 2 and R = 0 from case 3.

Your take?

Regards

You are taking it in a little wrong direction. By R>0 and RIt is stated that -
if X>0 then X| = +X
and if X
I think this should put some light upon my solution.

Anuj
4171

The ratio of two quantities is 3 to 4. If each of the
quantities is increased by 5, what is the ratio of these
two new quantities?

(A)
3/4

(B)
8/9

(C)
18/19

(D)
23/24

(E) It cannot be determined from the information
given.

4172
The ratio of two quantities is 3 to 4. If each of the
quantities is increased by 5, what is the ratio of these
two new quantities?

(A)
3/4

(B)
8/9

(C)
18/19

(D)
23/24

(E) It cannot be determined from the information
given.


Suppose the two numbers are 3 and 4. Now new ratio=
3+5:4+5 = 8:9

Similarly lets take two other numbers with ratio 3:4 =
12:16, so ratio after adding 5= 17:21

Like this everytime you might get different ratio, hence the answer cannot be determined from the information provided.
So, E is correct.

whats the OA?
4173

Yes. E is the right answer. Here is another one.

For a finite sequence of non zero numbers, the number of variations in sign is defined as the number of pairs of consecutive terms of the sequence for which the product of the two consecutive terms is negative. what is the number of variations in sign for the sequence 1, -3, 2, 5, -4, -6

one
two
three
four
five

can someone explain this.

4174
Yes. E is the right answer. Here is another one.

For a finite sequence of non zero numbers, the number of variations in sign is defined as the number of pairs of consecutive terms of the sequence for which the product of the two consecutive terms is negative. what is the number of variations in sign for the sequence 1, -3, 2, 5, -4, -6

one
two
three
four
five

can someone explain this.


If my understanding of questions is correct it says the number of variations in sign is equal to the number of pairs of consecutive terms for which product is negative.
Now the sequence is 1, -3, 2, 5, -4,-6

Product of first 2 consecutive terms= 1 x -3 = -3
Product of next 2 consecutive terms= -3 x 2 = -6
Product of next 2 consecutive terms= 2 x 5 = 10
Product of next 2 consecutive terms= 5 x -4 = -20
Product of next 2 consecutive terms= -4 x -6 = 24

Now the number of negative products= 3 (-3, -6 and -20)
Hence, the number variation of sign is three. My answer is C.

OA please?
4175
If my understanding of questions is correct it says the number of variations in sign is equal to the number of pairs of consecutive terms for which product is negative.
Now the sequence is 1, -3, 2, 5, -4,-6

Product of first 2 consecutive terms= 1 x -3 = -3
Product of next 2 consecutive terms= -3 x 2 = -6
Product of next 2 consecutive terms= 2 x 5 = 10
Product of next 2 consecutive terms= 5 x -4 = -20
Product of next 2 consecutive terms= -4 x -6 = 24

Now the number of negative products= 3 (-3, -6 and -20)
Hence, the number variation of sign is three. My answer is C.

OA please?


Yes. The answer is C. I understood your concept.
thanks.
4176

Hi,

Can someone please help me out with this question.

Find the range of values of x for which x^2 + 7x + 12 > 0.

I have factorized it to (x+3)(x+4) > 0. I don't know how to proceed after this.
Answer is x-3 but I am not able to understand how this was achieved.

Thanks in advance

4177

Hi

Since the product is +ve, both the terms are either +ve or -ve. So you get something like this:

(x+3)>0 and (x+4)>0 ----1

or

(x+3)
Simplifying the above 2 relations further, we get

x > -3 and x > -4, therefore x > -3

or

x
So you finally get x > -3 or x
Hope this helps

Regards
Tej


Hi,

Can someone please help me out with this question.

Find the range of values of x for which x^2 + 7x + 12 > 0.

I have factorized it to (x+3)(x+4) > 0. I don't know how to proceed after this.
Answer is x-3 but I am not able to understand how this was achieved.

Thanks in advance
4178

Thanks a lot for the reply :)

Hi

Since the product is +ve, both the terms are either +ve or -ve. So you get something like this:

(x+3)>0 and (x+4)>0 ----1

or

(x+3)
Simplifying the above 2 relations further, we get

x > -3 and x > -4, therefore x > -3

or

x
So you finally get x > -3 or x
Hope this helps

Regards
Tej
4179

can anyone tell me abt GMAT n its criteria of work exprce??? i 've no idea abt mBA entrance exams for foriegn study..

4180
anusha.m21 Says
can anyone tell me abt GMAT n its criteria of work exprce??? i 've no idea abt mBA entrance exams for foriegn study..


Most good B-Schools require at least 2 years of work-ex, as an unstated rule.

Refer this thread for further queries:

http://www.pagalguy.com/forum/gmat-and-related-discussions/55904-gmat-query-center-2010-11-a-9.html#post2383131
4181

If t=1/(2)9 * (5)3 is expressed as terminating decimal, how many zeros will t have between the decimal point and first non zero digit to the right of the decimal point?

A 3
B 4
C 5
D 6
E 7


Also can some one explain the concept of terminating decimal like if 1/11 has 2 decimal repeating ...

REGARDS
Atul

4182
If t=1/(2)9 * (5)3 is expressed as terminating decimal, how many zeros will t have between the decimal point and first non zero digit to the right of the decimal point?

A 3
B 4
C 5
D 6
E 7


Also can some one explain the concept of terminating decimal like if 1/11 has 2 decimal repeating ...

REGARDS
Atul



Sorry guys this is (2)ki power 9 and (5)ki power 3
4183

Two men left simultaneoulsy from P and Q,one of them left P for Q and the other left Q for P. Both travelled in their own uniform velocity.Having arrived at their respective destinations, they turned back to theri starting points wthout stopping.First time they met on their onward journey d1 km from P and the second time, on their return journey,they met d2 km from Q.If d is the distance between P and Q, then find d in terms of d1 and d2.

Options:
1)2d1-d2
2)3d1-d2
3)4d1-d2
4)5d1-d2
5)5d1-2d2

Puys, please explain this!!!

4184
Since you asked about terminal decimals:
A terminating decimal is a decimal that has a finite number of digits after the decimal point.
Example: 1/8 = 0.125 is a terminal decimal, however 1/6 = .1666666666666666 with the 6 repeating is NOT a terminal decimal.

A decimal is terminal if the denominator can be expressed as (2^x)(5^y).

1/((2^9)(5^3)) has a denominator that is expressed in the powers of 2 and 5 so is therefore a terminating decimal.

To approach the question

rewriting the denominator:
1/((2^9)(5^3)) = (1 /(2^3)(5^3)) * (1/ 2^6)
= (1/1000) * (1/64)
= 1/64,000

we know that 1/64,000 is less than 1/10,000 but greater than 1/100,000
in other words
1/100,000 .00001 .00001 thus there are 4 decimal points between the decimal point and the first non zero digit:

regards,
rajiv, gmat 750, awa 6
my gmat story

p.s. you can rephrase the answer choices as
Choice A - is between 0.0001 and 0.0009999999..
Choice B - is between 0.00001 and 0.0000999999..
choice C - is between 0.000001 and 0.0000099999..
Choice D - is between 0.0000001 and 0.0000009999..
Choice E - is between 0.00000001 and 0.0000009999...

Hope this helps. The answer should be B.



Thanks for this

But i have another query suppose a question is 1/11 and it ask us how many digits will repeat after decimal what will be our answer and Why?????
4185
Two men left simultaneoulsy from P and Q,one of them left P for Q and the other left Q for P. Both travelled in their own uniform velocity.Having arrived at their respective destinations, they turned back to theri starting points wthout stopping.First time they met on their onward journey d1 km from P and the second time, on their return journey,they met d2 km from Q.If d is the distance between P and Q, then find d in terms of d1 and d2.

Options:
1)2d1-d2
2)3d1-d2
3)4d1-d2
4)5d1-d2
5)5d1-2d2

Puys, please explain this!!!

Is the answer
3d1-d2.

The best way to arrive at the answer is to consider that they travel at equal speeds.
Hence they will always meet at the middle point of P and Q. Hence d1=d2=d/2
Now, If you look at the options, only option 2 satisfies the criteria :).