Dear All,
Can someone please solve the following two questions below--- (with explainations).--- I will post the answers later.
These questions are from Gmat prep ----
Q1) If n is a +ve integer & the product of all the integers from 1 to n, inclusive, is a multiple of 990, what is the least possible value of n?
choices---
10
11
12
13
14
Q2) for which of the following functions is f(a+b) = f(a) + f(b) for all the +ve nos a &b;?
choices---
f(x) = x 2 (it is x sqaure)
f(x) = x+1
f(x) = square root of x
f(x) = 2/x
f(x) = -3x
A quick reply would be appreciated.
warm regards,
Ranjit
Dear All,
Can someone please solve the following two questions below--- (with explainations).--- I will post the answers later.
These questions are from Gmat prep ----
Q1) If n is a +ve integer & the product of all the integers from 1 to n, inclusive, is a multiple of 990, what is the least possible value of n?
choices---
10
11
12
13
14
Q2) for which of the following functions is f(a+b) = f(a) + f(b) for all the +ve nos a &b;?
choices---
f(x) = x 2 (it is x sqaure)
f(x) = x+1
f(x) = square root of x
f(x) = 2/x
f(x) = -3x
A quick reply would be appreciated.
warm regards,
Ranjit
malwe aaleo...aah reha sada reply :-)
Q1 : 11
Q2 : f(x) = -3x
Dear All,
Can someone please solve the following two questions below--- (with explainations).--- I will post the answers later.
These questions are from Gmat prep ----
Q1) If n is a +ve integer & the product of all the integers from 1 to n, inclusive, is a multiple of 990, what is the least possible value of n?
choices---
10
11
12
13
14
1*2*..*n = 990k = 9*10*11 k
Least value of n occurs when k=1 i.e when n= 11
Q2) for which of the following functions is f(a+b) = f(a) + f(b) for all the +ve nos a &b;?
choices---
f(x) = x 2 (it is x sqaure)
f(x) = x+1
f(x) = square root of x
f(x) = 2/x
f(x) = -3x
dude..wats the difficulty in this? simply for each f(x) , you are reqd to check the condn.
-3(a+b)= (-3a) +(-3b)
others wont satisfy
A quick reply would be appreciated.
warm regards,
Ranjit
Regards
Neo
vicky.verma SaysExplainations ?? :-)
dude..for the last problem
Prob = 7C2 * 3C1 / 10C3
dude..i would appreciate if you point out your difficulty specifically rather than knowing my solution fully. That ways i may help you find your mistakes.
Give a try again to your problems. I' m sure you can solve them correctly this time:-)
NEO
yes go ahead.
This thread is for all those junta who will be appearing for GMAT.....
We dont have a proper GMAT discussion thread. Here I will post post GMAT related problems and discuss them.
Hope to see lots of participants
ans of q 1- is 11
and that of q 2 is last one..f(x) = -3x
jsut chech that
Dear All,
Can someone please solve the following two questions below--- (with explainations).--- I will post the answers later.
These questions are from Gmat prep ----
Q1) If n is a +ve integer & the product of all the integers from 1 to n, inclusive, is a multiple of 990, what is the least possible value of n?
choices---
10
11
12
13
14
Q2) for which of the following functions is f(a+b) = f(a) + f(b) for all the +ve nos a &b;?
choices---
f(x) = x 2 (it is x sqaure)
f(x) = x+1
f(x) = square root of x
f(x) = 2/x
f(x) = -3x
A quick reply would be appreciated.
warm regards,
Ranjit
Q.1
we know that the product of all integers from 1 to n is a multiple of 990 and we need the min. value of n....so the least multiple of 990 is 990 itself!!!
now,
990 = 3x3x2x5x11
since 11 should be present in the product of numbers from 1 to n, the least value of n is "11"..
hence, answer is B...
Q.2
case1:
f(x)=x2
f(a)=a2
f(b)=b2
f(a+b)=(a+b)2=a2+2ab+b2
f(a+b)f(a)+f(b)
case2:
f(x)=x+1
f(a)=a+1
f(b)=b+1
f(a+b)=a+b+1
f(a+b)f(a)+f(b)
case3:
f(x)=sqrt(x)
f(a)=sqrt(a)
f(b)=sqrt(b)
f(a+b)=sqrt(a+b)
f(a+b)f(a)+f(b)
case4:
f(x)=2/x
f(a)=2/a
f(x)=2/b
f(a+b)=2/(a+b)
f(a+b)f(a)+f(b)
case5:
f(x)=-3x
f(a)=-3a
f(b)=-3b
f(a+b)=-3(a+b)
f(a+b)=f(a)+f(b)
hence, correct answer is E...
Vicky the first problem you attached of coordinate geometry, the answer would be C.
For the letters a and b I pick numbers 1 and 2.
The first statement xy greater than 0 is insuficient as -x could be -1 if x is possitive but could be 1 if x is negative. With y it could be possitive and negative too.
The second statement ax greater than 0 means that Eg. a could equal 1 and so x equal 1 too. It is not enough to solve the problem (it doesnt say anything about y).
Consider both statments together x and y must be positive so (-x,y) are in the same quadrant (cuadrant II) that -a, b.
Vicky the second attached problem (coordinate geometry) I would go with C.
Statement 1 is insuficient as the only thing we know is that the slope is negative and that passes through point (0,0) origin.
Statement 2 is also insufficient as if a is less than b Eg a equals 2 so b could be 3; but if a equals -2, b could equals -3?
Joining statement 1 and 2, with a negative slope cuadrant II is the only case when a is less than b. So you can answer that b is positive.
Vicky the 3rd problem (if c and d are integers...) I would go with C.
Statement (1) c can be even and d odd or even or c and c and d can be both odd. In sum you have EO, EE and OO.
Statement (2) c can be even and d even, c can b even and d odd and c can be odd and d even. In sum EE, EO, OE
Both statements together you have EE or EO in both cases c is even.
Vicky the 4th problem you attached (is xy greater than 0) I will go with E.
Statement 1: x - y greater than -2. You cant know wheter x or y are positive or negative, etc.
Statement 2: x -2y is less than -6 You cant know whether x or y are positive or negative.
DS :
What is the sum of 5 evenly spaced integers in a set?
- The median of the set of numbers is 0.
- The range of the numbers in the set is 4.
B) Statement (2) BY ITSELF is sufficient, but statement (1) by itself is not sufficient.
C) Both statements TAKEN TOGETHER are sufficient, but NEITHER statement BY ITSELF is sufficient.
D) EACH statement BY ITSELF is sufficient.
E) The two statements TAKEN TOGETHER are NOT sufficient.
DS :
What is the sum of 5 evenly spaced integers in a set?A) Statement (1) BY ITSELF is sufficient, but statement (2) by itself is not sufficient.
- The median of the set of numbers is 0.
- The range of the numbers in the set is 4.
B) Statement (2) BY ITSELF is sufficient, but statement (1) by itself is not sufficient.
C) Both statements TAKEN TOGETHER are sufficient, but NEITHER statement BY ITSELF is sufficient.
D) EACH statement BY ITSELF is sufficient.
E) The two statements TAKEN TOGETHER are NOT sufficient.
Answer would be A .
Explanation :
A : Since the median is 0 and since the set contains 5 numbers so the middle nunmber is 0 since the median is 0 .
and since they are evenly spaced.....2 would be on negative side and two others would be on the positive side and since they are evenly spaced they would be of same distance from 0 . Thereby making the sum of all 0 . Thus A would be sufficeient to answer .
Ex : -6 -3 0 +3 +6 .
B : Lets use Pick the Numbers principle now :
Numbers chosen : 0 1 2 3 4 ----Range is : 4 . Sum : 10
Numbers chosen : 3 4 5 6 7 --- Range is : 7-3=4 . Sum : 25 .
Therefore it is not suffiecient .
Therefor tegh Answer is A .
Regards,
Flintoff
hi,
Here is a DS question from GMAT power prep software,the correct answer for which is not explained properly.I'm hoping someone can explain it to me.Thanks in advance.
Raj
x,y are integers.Are x and y both positive?
i) 2x-2y=1
ii) x/y >1
hi,
Here is a DS question from GMAT power prep software,the correct answer for which is not explained properly.I'm hoping someone can explain it to me.Thanks in advance.
Raj
x,y are integers.Are x and y both positive?
i) 2x-2y=1
ii) x/y >1
I say the answer should be C .
Reason :
Take A : Its impossible for us to know about x and y from the equation x-y = 0.5 .
for this equation t be satisfid we can have x and y positive or negatve or one as 0 and other as positive or negatie . We can have absolutely any combinations . Thereby making A insufficient .
So rule out options A and D . Left with B C E .
Now take B :
x/y>1........ Implies :
Both x and y should be of same sign for this equation to be satisfied else value would be negative .
Now if + :
x shouuld be greater than y for x/y>1........So both x and y are positive .
Now if - : x should be always lesser than y . Ex : x = -7.5 y = -7 . etc etc . So we have more than choice that x and y can be both + and - . Thereby B becoming insufficient .
Rule out B .
Left out with C and E .
Now if we take both choices together :
Can be possible only if x and y are either positive simultaneously or x and y are negative . Both cant be of different signs at once since it does not satisfy the B as shown above .
Now , If x and y are negative as shown :
It does not satisfy A but satisfies B .
Ex : for x/y>1 in case of negatives : x should be lesser than y . Ex : x=-7.5 and y = -7
In this case in A : -7.5+7 = -0.5 . which never satisfies A .
Therefore x and y should alwways be positive .
Answer being C .
I say the answer should be C .
I 2nd this solution.
Ex : for x/y>1 in case of negatives : x should be lesser than y . Ex : x=-7.5 and y = -7
In this case in A : -7.5+7 = -0.5 . which never satisfies A .
Therefore x and y should alwways be positive .
Answer being C .
Perfect reasoning....but I got a doubt here... is -7.5 an integer...
Dear All,
this email is with reference to the following problem--
i) 2x-2y=1
ii) x/y >1
***************
x and y are integers. Then how can we take values as 7.5 ?
secondly x is supposed to be geater than y as per B. Then how can we take x as -7.5 and y as -7 (on the number line -7 comes first) ?
cheers,
ranjit
hi,
Here is a DS question from GMAT power prep software,the correct answer for which is not explained properly.I'm hoping someone can explain it to me.Thanks in advance.
Raj
x,y are integers.Are x and y both positive?
i) 2x-2y=1
ii) x/y >1
since x and y are integers 2x-2y=1 is not possible.
now from statement 2 x and y have same sign and x is greater than y we cannot confirm about whether they are positive or not
so both statements are not sufficient.