Anyone tried :
GMAT Prep Question
How many factors does 36^2 have?
(A) 2
(B) 8
(C) 24
(D) 25
(E) 26
What is the best approach?
OA is (D)
How many factors does 36^2 have?
(A) 2
(B) 8
(C) 24
(D) 25
(E) 26
What is the best approach?
OA is (D)
36^2 - (3^2 * 2^2)^2.
= 3^4 * 2^4.
So total no.of factors can be 5*5 = 25 factors.
-Deepak.
36^2 - (3^2 * 2^2)^2.
= 3^4 * 2^4.
So total no.of factors can be 5*5 = 25 factors.
-Deepak.
I get the point that 36^2 = 2^4 * 3^4.
From this, how can you arrive at the fact that the total no. of factors would be 5*5 = 25?
Please explain.
How many factors does 36^2 have?
(A) 2
(B) 8
(C) 24
(D) 25
(E) 26
What is the best approach?
(D) 25........
I get the point that 36^2 = 2^4 * 3^4.
From this, how can you arrive at the fact that the total no. of factors would be 5*5 = 25?
Please explain.
There is a formula for that:
N = a^p * b^q * c^r where a,b,c are all prime and p,q,r are all integers then total no.of factors of N will be (p+1)*(q+1)*(r+1).
-Deepak.
The population of locusts in a certain swarm doubles every two hours. If 4 hours ago there were 1,000 locusts in the swarm, in approximately how many hours will the swarm population exceed 250,000 locusts?
6
8
10
12
14
OA is 12
What is the best approach to solve above types of problems (other than creating a population chart)?
The population of locusts in a certain swarm doubles every two hours. If 4 hours ago there were 1,000 locusts in the swarm, in approximately how many hours will the swarm population exceed 250,000 locusts?
6
8
10
12
14
OA is 12
What is the best approach to solve above types of problems (other than creating a population chart)?
We can solve this using GP taking a = 1000 and r = 2 every 2 hrs but fastest way is to solve using the chart itself.
-Deepak.
A family consisting of one mother, one father, two daughters and a son is taking a road trip in a sedan. The sedan has two front seats and three back seats. If one of the parents must drive and the two daughters refuse to sit next to each other, how many possible seating arrangements are there?
a) 28
b) 32
c) 48
d) 60
e) 120
Any suggestions for solving this quickly?
OA is b) 32
Hi Friends
Probability & PnC are a weak area, any help or suggestion wld be appreciated. I wld be taking my GMAT on the 17th.
Rgds
Tej
Hi Friends
Probability & PnC are a weak area, any help or suggestion wld be appreciated. I wld be taking my GMAT on the 17th.
Rgds
Tej
Probability and PnC are two sets of problems in which even the simplest of questions can be tricky if you are not thorough with the basics. You can practice a little more on them through GMAT Official Guide Quantitative Review. Try and understand the basics properly and then these topics would be a cake walk for you.
Good Luck for your preparation.
Anuj
Dear Anuj
For basics would you recommend any particular book, OG was very very basic.
Tej
Dear Anuj
For basics would you recommend any particular book, OG was very very basic.
Tej
GMAT quantitative section comprises of High School level questions. So if Official Guide is not serving your purpose (which is hard to digest as it is the best book to refer to) you can go back to your high school books to clarify your concepts.
Good Luck for your prep!
Anuj
Hi Friends,
Q-All of the stocks on the o-t-c market are designated by either a 4-letter or a 5-letter code that is created by using the 26 letters of the alphabet. Which of the following gives the maximum number of different stocks that can be designated with these codes?
A) 2(26)^5
B) 26(26)^4
C) 27(26)^4
D) 26(26)^5
E) 27(26)^5
Any suggestions for solving this.
OA is C.
Hi Friends,
Q-All of the stocks on the o-t-c market are designated by either a 4-letter or a 5-letter code that is created by using the 26 letters of the alphabet. Which of the following gives the maximum number of different stocks that can be designated with these codes?
A) 2(26)^5
B) 26(26)^4
C) 27(26)^4
D) 26(26)^5
E) 27(26)^5
Any suggestions for solving this.
OA is C.
For the four letter stock the four letters in the stock can be taken up by 26 letters each.
So 26 * 26 * 26 * 26 = 26^4
Same for the five letter stocks = 26^5
Since a stock can be either a four letter or a five letter stock ( Mutually exclusive events)
Answer : 26^4 + 26^5 = (27) * (26 ^4)
Hi Friends
Probability & PnC are a weak area, any help or suggestion wld be appreciated. I wld be taking my GMAT on the 17th.
Rgds
Tej
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
R^3 + R = 0
find the possible values of R..
as problems does not seem to be very tough...
my take was R= 0,-1,+1
but in explanation R = 0,-1 BUT NOT +1.
can somebody explain ?????
R^3 + R| = 0
find the possible values of R..
as problems does not seem to be very tough...
my take was R= 0,-1,+1
but in explanation R = 0,-1 BUT NOT +1.
can somebody explain ?????
R^3 + R = 0
R = - R^3
R cannot be +1 , because if we substitute R for 1 in above equation , we get
|+1 = -(+1)^3
which results in +1 = -1 .
Hence R cannot take the value of +1.
Hope that helps
Dear Anuj
For basics would you recommend any particular book, OG was very very basic.
Tej
Harvard MBA alumni explains all maths concepts . more than 3 Lakh users learn maths here everyday.
Probability is explained here :
Probability (part 1) | Khan Academy
Solution to all GMAT OG ::
Khan Academy
R^3 + R| = 0
find the possible values of R..
as problems does not seem to be very tough...
my take was R= 0,-1,+1
but in explanation R = 0,-1 BUT NOT +1.
can somebody explain ?????
When its a modulus you take both the cases when R>0 and when RCase 1 - When R > 0
R = +R
So the expression now becomes -
R^3 + R = 0
R(R^2 + 1) = 0
This would give R=0 as a possible value
Case 2 - When R|R= -R
So the expression now becomes -
R^3-R=0
R(R^2-1)=0
Solving the above you would get R=0,+1, -1 as possible values.
But put back R= +1 in the above expression and it doesn't satisfy so we omit this value.