Hi Alchemist,
Correct me if I am wrong or assuming too much. But I thought A would be enough to answer the question.
a^-3 b^-2 = 36^-1
or 1/a^3 b^2 = 1/36
1/36 = 1/6^2 which is only possible if a=1 and b=6; (we can not break 6 further into 3*2 because then either 3^2 and 2^2 is not equal to a^3 and b^2.)
Hi Alchemist,
Correct me if I am wrong or assuming too much. But I thought A would be enough to answer the question.
a^-3 b^-2 = 36^-1
or 1/a^3 b^2 = 1/36
1/36 = 1/6^2 which is only possible if a=1 and b=6; (we can not break 6 further into 3*2 because then either 3^2 and 2^2 is not equal to a^3 and b^2.)
Sure - you assumed a & b to be positive integers... positive is correct, but integers we don't know.. and hence we need both the sentences to zero in the answer.
I surely agree with you guys, the answer is E, however , i was thinking that there is an assumption which they did not mention in the question.
Anyway, thanks ankitgarg and alchemist-mba !!
Well here is another one.
This a DS question :
What is the value of a^-2 b^-3?
(1) a^-3b^-2 = 36^-1
(2) ab^-1 = 6^-1
E.
Whats the OA?
Q1 : Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?
A. k m %
B. (k m) %
C. / (100 + k) %
D. / (100 + m) %
E. / (100 + k + m) %
Q.2: If x
A. -x
B. -1
C. 1
D. x
E. x
A. k m %
B. (k m) %
C. / (100 + k) %
D. / (100 + m) %
E. / (100 + k + m) %
Q.2: If x
A. -x
B. -1
C. 1
D. x
E. x
Q1 : Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?
A. k m %
B. (k m) %
C. / (100 + k) %
D. / (100 + m) %
E. / (100 + k + m) %
Q.2: If x
A. -x
B. -1
C. 1
D. x
E. x
My Take --> Q1: D, Q2: A
Q1: let price per share be 'a'
earning per share be 'b'
Prior to Increase: Ratio of price per share to earning per share is (a/b)
Post Increase:
Ratio --> (a + (a *k/100)) / (b + (b *m/100))
=> (a/b) (1+k/100)(1+m/100)
=> (a/b) (100+k/100+m)
Lets say, increase % be t
=> (a/b) + (a/b) * (t/100) = (a/b) (100+k/100+m)
=> 1 + (t/100) = (100+k/100+m)
solving for t, we get t = (k-m) (100) / (100+m)
2. Let x = -5 => (-xx) = (5)(5) = 5 = -x
What are the OA's?
Q1 : Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?
A. k m %
B. (k m) %
C. / (100 + k) %
D. / (100 + m) %
E. / (100 + k + m) %
Q.2: If x
A. -x
B. -1
C. 1
D. x
E. x
1)
let price per share=a
earnings per share=b
old PE ratio: a/b
after increase in price per share by k%, the new value bcums: (1+k/100)*a
after increase in earnings per share by m%, the new value bcums: (1+m/100)*b
new PE ratio: /
%change in PE ratio: /old PE ratio * 100
i.e.
{/ - a/b} / {a/b} *100 = / (100 + m)
2)
let x= -3
x|=3
sqrt(-x*|x)= sqrt(3*3) = 3 = -(-3) = -x
revert incase of doubts
My Take --> Q1: D, Q2: A
Q1: let price per share be 'a'
earning per share be 'b'
Prior to Increase: Ratio of price per share to earning per share is (a/b)
Post Increase:
Ratio --> (a + (a *k/100)) / (b + (b *m/100))
=> (a/b) (1+k/100)(1+m/100)
=> (a/b) (100+k/100+m)
Lets say, increase % be t
=> (a/b) + (a/b) * (t/100) = (a/b) (100+k/100+m)
=> 1 + (t/100) = (100+k/100+m)
solving for t, we get t = (k-m) (100) / (100+m)
2. Let x = -5 => (-xx) = (5)(5) = 5 = -x
What are the OA's?
hi alchemist-mba,
1. what is the difference between increase in earnings per share and increase in share.
isn't it the same?
2. And isn't -(-5)(-5) = (5)(5) = 25 = +5, -5 ?
hi alchemist-mba,
2. And isn't -(-5)(-5) = (5)(5) = 25 = +5, -5 ?
There you go...all my maths concept got shaken when I came to know that OA for this question is -x because I too assumed and assume that sqrt (x^2) can be +/-x. :huh:
But some how finally concluded that as per GMAT math's definition, it can only be +x i.e domain of sqrt function can only be +ve values, so we have to follow that only.
There you go...all my maths concept got shaken when I came to know that OA for this question is -x because I too assumed and assume that sqrt (x^2) can be +/-x. :huh:
But some how finally concluded that as per GMAT math's definition, it can only be +x i.e domain of sqrt function can only be +ve values, so we have to follow that only.
In this particular question it is told that x
ashishjha100 SaysIn this particular question it is told that x
oops!
I missed it
Should be 'C' both are required..
using 1 or 2 - we cannot get a^-2 b^-3, but using both we can get value of a and b - from which a^-2 b^-3 can be solved.
My ans is C too..
From 2 we get b=6a. Substituting in 1, we can have value of a^-2b^-3.
ashishjha100 SaysIn this particular question it is told that x
sqrt of 25 can never be -5.
x^2=25 have 2 solutions as 5,-5. But x=sqrt(25) has single sol as 5.
You can interpret it as a quad eq will necessarily have 2 soln whereas linear eq will have only 1 soln.
Likewise x^n=cnst will have n solutions of which some may be imagenary.
Ashish
sqrt of 25 can never be -5.
x^2=25 have 2 solutions as 5,-5. But x=sqrt(25) has single sol as 5.
You can interpret it as a quad eq will necessarily have 2 soln whereas linear eq will have only 1 soln.
Likewise x^n=cnst will have n solutions of which some may be imagenary.
Ashish
Hi Ashish,
Please dont get confused
x^2 = 25 and x = sqrt(25), both will have 2 solutions.
hi alchemist-mba,
1. what is the difference between increase in earnings per share and increase in share.
isn't it the same?
2. And isn't -(-5)(-5) = (5)(5) = 25 = +5, -5 ?
1.Price per share is the cost at which you bought the share and earning
per share aka EPS is different... you need to have 'stock market'
knowledge to really know this... but for us 😉 all we need to think is
there are two unknown values.. not really bothered about their actual
meaning...
2. X .
Since, there should be a single answer - -always, GMAT will have an unique solution..
Hope it helps....
My Take --> Q1: D, Q2: A
Q1: let price per share be 'a'
earning per share be 'b'
Prior to Increase: Ratio of price per share to earning per share is (a/b)
Post Increase:
Ratio --> (a + (a *k/100)) / (b + (b *m/100))
=> (a/b) (1+k/100)(1+m/100)
=> (a/b) (100+k/100+m)
Lets say, increase % be t
=> (a/b) + (a/b) * (t/100) = (a/b) (100+k/100+m)
=> 1 + (t/100) = (100+k/100+m)
solving for t, we get t = (k-m) (100) / (100+m)
2. Let x = -5 => (-xx) = (5)(5) = 5 = -x
What are the OA's?
You are right answer is D and A. For second question I thought the answer to be X. But now its clear. Thanks.
Hi Puys,
Help me in these 2 questions.
You can find them in the attached doc file.
These are from GMATprep.
Please give explanations also.
Hi Puys,
Help me in these 2 questions.
You can find them in the attached doc file.
These are from GMATprep.
Please give explanations also.
Q1. it is 40% increase - D
Rate = C (a constant) *
B is increased by 100% => its 2B
Let new conc of A be A1
To keep at the same level =>
C * = C *
=> Solving for A1 we get it to be square-root(2) * A
=> A + A * (X/100) = square-root(2) * A
=> (x/100) = square-root(2) - 1 => approximately 1.414 - 1 = .414
=> % increase is 41.4% ----- hence D
Hi Puys,
Help me in these 2 questions.
You can find them in the attached doc file.
These are from GMATprep.
Please give explanations also.
Q2. Is tricky..
It is given.. 'could be' not should be....
e.g take x = 1/4
then x^2
take x = 10/11
then x^2
But III can never occur.. cos x^2 is > 2x after point (2,0) but then 1/x can never be greater than either of these two beyond that point.. and hence I & II are correct... So the answer is 'D'
Good questions
How about this one guys....
Kurt, a painter, has 9 jars of paint:
4 are yellow
2 are red
rest are brown
Kurt will combine 3 jars of paint into a new container to make a new color, which he will name accordingly to the following conditions:
Brun Y if the paint contains 2 jars of brown paint and no yellow
Brun X if the paint contains 3 jars of brown paint
Jaune X if the paint contains at least 2 jars of yellow
Jaune Y if the paint contains exactly 1 jar of yellow
What is the probability that the new color will be Jaune
a) 5/42
b) 37/42
c) 1/21
d) 4/9
e) 5/9
Thanks in advance.
Kurt, a painter, has 9 jars of paint:
4 are yellow
2 are red
rest are brown
Kurt will combine 3 jars of paint into a new container to make a new color, which he will name accordingly to the following conditions:
Brun Y if the paint contains 2 jars of brown paint and no yellow
Brun X if the paint contains 3 jars of brown paint
Jaune X if the paint contains at least 2 jars of yellow
Jaune Y if the paint contains exactly 1 jar of yellow
What is the probability that the new color will be Jaune
a) 5/42
b) 37/42
c) 1/21
d) 4/9
e) 5/9
Thanks in advance.
Another one......
TWO couples and a single person are to be seated on 5 chairs such that no couple is seated next to each other. What is the probability of the above??
Explanations please....