Is
? (1/x)
1. x >0
2. x
Does such kind of Q appear in GMAT??
One suggestion Avik, No need to post the options for a standard DS question. All puys are intelligent enough to understand the 5 options presented in all DS questions on the GMAT.
Coming back,
I will not solve this one, I will try to help you reach the answer,
if you still do not get it, please post your understanding and we can discuss further.
Is sqrt{(x-3)^2}= 3-x
Did you understand this prompt clearly?
Try and use this information:
sqrt(x^2) = x| as the square root of a number is always positive.
For this question, replace the x in the above equation by x-3.
Let's also decode Statement 2.
-xx > 0
(-x) * x > 0
For any value to be +ve, both parts should either be +ve, or both should be -ve.
Since x is always +ve, we now know the other part (-x) is +ve.
Since -x >0, x
So this statement actually wanted to tell us that x
Use these information and let us know your approach after you have this info.
Sorry if the 5 options gave an indication that I was undermining anybody's intellectual capacity..
I have just one query here.. why is sqrt(x^2) = |x?? Shouldnt a sqrt function give both the +ve and -ve versions of a number???
This was basically my query.
I ran into the following question
In the xy-plane, does the line with equation y=3x+2 contain the point (r,s)?
1) (3r+2-s)(4r+9-s)=0
2) (4r-6-s)(3r+2-s)=0
I am hoping someone can help me with the following.
a) What does the question translate to?
"The options given are equations for (r,s). Check for..................?"
b) Since I had to choose an answer I substituted (r,s) in y=3x+2. I got s=3r+2. If so in option #1 the first term reduces to zero on substituting for s. Similarly in option #2 the second term reduces to zero.
Thus I went for "question can be answered using either statement alone". However correct option is "using both statements together".
Possibly once (a) is clarified I will understand how (b) went wrong. Thanks.
I ran into the following question
I am hoping someone can help me with the following.
a) What does the question translate to?
"The options given are equations for (r,s). Check for..................?"
b) Since I had to choose an answer I substituted (r,s) in y=3x+2. I got s=3r+2. If so in option #1 the first term reduces to zero on substituting for s. Similarly in option #2 the second term reduces to zero.
Thus I went for "question can be answered using either statement alone". However correct option is "using both statements together".
Possibly once (a) is clarified I will understand how (b) went wrong. Thanks.
s=3r+2, to simplify, lets put a couple of values for r,s ... r=0 => s=2; r=1 =>s=5;
now lets look at the equations,
when we put r=0, we get s=2/9, not sufficient right
in second one, r=0 => s=2/-6, not sufficient
put another value... r=1 => s=5/13
in second one, r=1 => s=5/-2
you can generalize based on this (of course you need to solve the equations to generalize but you can get the idea by putting values) that every time you put some value in both, both equations will give 2 solutions; so each alone is not sufficient, but you take both and you've got a unique answer. hence together sufficient.
s=3r+2, to simplify, lets put a couple of values for r,s ... r=0 => s=2; r=1 =>s=5;
now lets look at the equations,
when we put r=0, we get s=2/9, not sufficient right
in second one, r=0 => s=2/-6, not sufficient
put another value... r=1 => s=5/13
in second one, r=1 => s=5/-2
you can generalize based on this (of course you need to solve the equations to generalize but you can get the idea by putting values) that every time you put some value in both, both equations will give 2 solutions; so each alone is not sufficient, but you take both and you've got a unique answer. hence together sufficient.
and you can even do it even more simpler way by:
for point to be on line it need to satisfy.. s = 3r+2
in first equation: s = 3r+2 and s = 4r+9
similarly in second: s=4r-6 and s=3r+2
so neither is sufficient alone but together they give s=3r+2
GMAT prep:
Isosceles triangle RST, Angle T = ?
1. Angle R=100
2. Angle S=40
ans:A
If carlos took 1/2 hr to drive by cycle.. Was the distance he covered was more that 6feel?
1. Avg speed he drove cycle was greater than 16feet/sec
2. Avg speed he drove cycle was greater than 18 feet/sec
ans:E
# denote : + or - or / or *..(6#2)#4 = 6#(2#4) ?
1. 3#2 > 3
2. 3#1 = 3
ans :A
Sorry if the 5 options gave an indication that I was undermining anybody's intellectual capacity..
I have just one query here.. why is sqrt(x^2) = x|?? Shouldnt a sqrt function give both the +ve and -ve versions of a number???
This was basically my query.
Arre dost, you took it the wrong way because I forgot the smiley :)
Its just that everyone knows the options, giving them makes the post longer, that is all, nothing else. Please do not read too much into what was said. Peace. :cheers:
Coming to your query,
For all real numbers, sqrt function gives the +ve value only.
Because square root of a number is always positive (In case of GMAT, http://www.manhattangmat.com/forums/is-sqrt-x-3-2-3-x-t7258-15.html).
That is the reason, sqrt(x^2) = |x
Some more for better understanding,
^2 = x, will always be true for any x.
but, sqrt =! x, unless x is a +ve number.
s=3r+2, to simplify, lets put a couple of values for r,s ... r=0 => s=2; r=1 =>s=5;
now lets look at the equations,
when we put r=0, we get s=2/9, not sufficient right
in second one, r=0 => s=2/-6, not sufficient
put another value... r=1 => s=5/13
in second one, r=1 => s=5/-2
you can generalize based on this (of course you need to solve the equations to generalize but you can get the idea by putting values) that every time you put some value in both, both equations will give 2 solutions; so each alone is not sufficient, but you take both and you've got a unique answer. hence together sufficient.
Arre dost, you took it the wrong way because I forgot the smiley :)
Its just that everyone knows the options, giving them makes the post longer, that is all, nothing else. Please do not read too much into what was said. Peace. :cheers:
Coming to your query,
For all real numbers, sqrt function gives the +ve value only.
Because square root of a number is always positive.
That is the reason, sqrt(x^2) = x
Some more for better understanding,
^2 = x, will always be true for any x.
but, sqrt =! x, unless x is a +ve number.
dost, sqrt of a function is not Always positive. it's positive square root and negative square root as well.
sqrt(4) is -2 also right. -2 X -2 = 4
dost, sqrt of a function is not Always positive. it's positive square root and negative square root as well.
sqrt(4) is -2 also right. -2 X -2 = 4
IT IS my friend, dont believe me, check this post, the 4th answer is by Ron, and when Ron says anything, the whole MGMAT community sits up and listens, so we also better do :
if x
IT IS my friend, dont believe me, check this post, the 4th answer is by Ron, and when Ron says anything, the whole MGMAT community sits up and listens, so we also better do :
if x
I know. I had already read it. Atleast he's telling the right reason behind that. You just went ahead and said that "Because square root of a number is always positive." ... that's a bold claim.
You're partially right, but try to understand the reason behind why you're right. square root is not positive, Root sign(number) or sqrt(number) is positive. I'd suggest that you go back and read the post again. and here is one more link where i had asked Ron about the same thing and he answered. for your reference:
Is sqrt((x-3)^2) = 3 - x? € Manhattan GMAT Forums
(9th post)
and dost, ye sab maine friendly mood mein likha hai.. jyada seriously mat lena ki ye to merko jaake posts read karne bol raha hai teacher ke jaise.. chilll. 😃
I know. I had already read it. Atleast he's telling the right reason behind that. You just went ahead and said that "Because square root of a number is always positive." ... that's a bold claim.
You're partially right, but try to understand the reason behind why you're right. square root is not positive, Root sign(number) or sqrt(number) is positive. I'd suggest that you go back and read the post again. and here is one more link where i had asked Ron about the same thing and he answered. for your reference:
Is sqrt((x-3)^2) = 3 - x? € Manhattan GMAT Forums
(9th post)
and dost, ye sab maine friendly mood mein likha hai.. jyada seriously mat lena ki ye to merko jaake posts read karne bol raha hai teacher ke jaise.. chilll. :)
I assumed that this was understood, my folly
Will edit the earlier post, just for clear understanding of anyone reading these posts:
Source: http://www.manhattangmat.com/forums/is-sqrt-x-3-2-3-x-t7258-15.html
In GMAT,
the square root of a number is ALWAYS the positive root only (or zero if the number is zero). This is confusing, so let me illustrate:
1) if x^2=4, then x can be 2 or -2.
2) However, if I am asked the square root of 4, it is only positive 2. There are no negative square roots on the GMAT
Explicit !
Hi guys
how long will it take 9 men n 6 women to complete a given task
1.6men n 3women takes 12hrs to complete a task twice as big as this task
2. 6men n 4women take 19hrs to complete a task thrice as big as this task
Hi guys
how long will it take 9 men n 6 women to complete a given task
1.6men n 3women takes 12hrs to complete a task twice as big as this task
2. 6men n 4women take 19hrs to complete a task thrice as big as this task
I would go with option B for the above DS.
statement2 * 1.5 times will give the ans
-Deepak.
I would go with option B for the above DS.
statement2 * 1.5 times will give the ans
-Deepak.
OA is option b
Q1: Symbol # represents one of the 4 arithmetic operations: Addition, subtraction, multiplication, division. Is (5#6)#2 = 5#(6#2)?
1) 5#6 = 6#5
2) 2#0 = 2
Ans: A
Q2: Is X^4 + Y^4 > Z^4
1) X^2 + Y^2 > Z^2
2) X + Y > Z
Ans E
If 20 Swiss Francs is enough to buy 9 notebooks and 3 pencils, is 40 Swiss Francs enough to buy 12 notebooks and 12 pencils?
(1) 20 Swiss Francs is enough to buy 7 notebooks and 5 pencils.
(2) 20 Swiss Francs is enough to buy 4 notebooks and 8 pencils.
Can some one help in this inequality question....
Hi,
I came across this question but could not figure out the answer.
Is n^p an odd integer?
(I) n is an odd integer.
(II) p is an even integer
The OA is E. But acc to me it should be A.
Please explain.
If 20 Swiss Francs is enough to buy 9 notebooks and 3 pencils, is 40 Swiss Francs enough to buy 12 notebooks and 12 pencils?
(1) 20 Swiss Francs is enough to buy 7 notebooks and 5 pencils.
(2) 20 Swiss Francs is enough to buy 4 notebooks and 8 pencils.
Can some one help in this inequality question....
Is the answer D......u can solve by eeither of the statements?
and i think u dont hve to give importance to the inequality coz u dont hav to find the exact answer....u just hav to see whether it can be solved or not....
so if u just take it as a regualr equation.....
u get one linear equation from the data given.........and another from each of the statement...u have two equations...and two knowns...solve for dem and substitue in the equation required..i.e 12x +12y = 40?
Hi,
I came across this question but could not figure out the answer.
Is n^p an odd integer?
(I) n is an odd integer.
(II) p is an even integer
The OA is E. But acc to me it should be A.
Please explain.
1st statement when n is odd.e.g 3 then P can be any integer -3 or 2 so when P is negative integer n^p will not be an integer so not sufficient
2nd statement when p is even. no information given about n if its odd then n^p is odd otherwise even ....SO not sufficient so answer is E.
Please correct me If I m wrong
Is the answer D......u can solve by eeither of the statements?
and i think u dont hve to give importance to the inequality coz u dont hav to find the exact answer....u just hav to see whether it can be solved or not....
so if u just take it as a regualr equation.....
u get one linear equation from the data given.........and another from each of the statement...u have two equations...and two knowns...solve for dem and substitue in the equation required..i.e 12x +12y = 40?
The answer is B and it is explained below
Given , question is true? Or is true? So basically we are asked whether we can substitute 3 notebooks with 3 pencils. Now if we can easily substitute notebooks with pencils (equal number of notebooks with pencils ) and the sum will be lees than 20. But if we won't know this for sure.
But imagine the situation when we are told that we can substitute 2 notebooks with 2 pencils. In both cases ( or ) it would mean that we can substitute 1 (less than 2) notebook with 1 pencil, but we won't be sure for 3 (more than 2).
(1) . We can substitute 2 notebooks with 2 pencils, but this not enough. Not sufficient.
(2) . We can substitute 5 notebooks with 5 pencils, so in any case ( or ) we can substitute 3 notebooks with 3 pencils. Sufficient.
Answer: B..
I dint get the Explanation