If the terms of the sequence are t1, t2, t3...tn, the sum of the n terms is 3124 and the average of the n terms is 4, what is n?
paki SaysIf the terms of the sequence are t1, t2, t3...tn, the sum of the n terms is 3124 and the average of the n terms is 4, what is n?
t1, t2, t3...tn, the sum of the n terms is 3124
=> t1 + t2 + t3 ..... +tn = 3124
the average of the n terms is 4
=> (t1 + t2 + t3 ..... +tn)/ n = 4
=> t1 + t2 + t3 ..... +tn = 4n = 3124
=> n = 781?
Whats the OA?
there is no OA (it was a data sufficiency problem which I convert to PS. OA of DA was C)
A certain company that sells only cars and trucks reported that revenues from car sales in 1997 were down 11 percent from 1996 and revenues from truck sales in 1997 were up 7 percent from 1996. If total revenues from car sales and truck sales in 1997 were up 1 percent from 1996, what is the ratio of revenue from car sales in 1996 to revenue from truck sales in 1996?
A. 1:2
B. 4:5
C. 1:1
D. 3:2
E. 5:3
The OA is A.
Can some one please solve this one with reasons!
Dude...good practice is not to provide the OA right away with the question. Let the puys attempt it and then post the OA after sometime. Knowing the OA sometimes deflect our approach towards the problem.
Thanks!
Following is a DS question
Q. Does
x = y?
(1) x = y
(2) x^2 = y^2
I have a doubt...Should we consider x and y to be negative after removing the mod sign? Is it typical to assume any number as negative after the mod sign is removed?
MSD
@ MSD
If nothing is given about X and Y, do not assume that they are positive/negative. Try to validate that the given condition satisfies ALL options for X and Y i.e positive, negative, fraction.
And thats why the answer is E.
Hope it helps!
Dude...good practice is not to provide the OA right away with the question. Let the puys attempt it and then post the OA after sometime. Knowing the OA sometimes deflect our approach towards the problem.
Thanks!
Hi,
Revenues from sales of Truck and Cars
In 96 let the revenues of Truck and Cars be x y
In 97 the revenues will be 0.89x 1.07y
Total Sales in 96 = z (x+y)
Sales in 97 = 1.01z
on equating ......1.01 (x+y) = 0.89x + 1.07y
solving this x/y = 1/2 whic is nothing but the ratio of truck/car sales
regards
madhav
Hey Sorry, Didn't think that way...
Will keep it that way from now....
Thanks for the advice madhav!
Pls help......
ashishjha100 SaysPls help......
I'll try to explain 5,6 and 7 -
5. If vmt 0, is v^2m^3t^4 > 0 ?
There will be a doubt that the expression is less than zero if m is -ve as in that case m^3 will also be negative. v^2 and t^4 will always be +ve.
Option 1 : m > v^2
This means m is a positive value as its greater than v^2 which will definitely be +ve. Hence, v^2m^3t^4 > 0. Sufficient.
Option 2 : m > t^4
This means m is a positive value as its greater than t^4 which will definitely be +ve. Hence, v^2m^3t^4 > 0. Sufficient.
Answer will be D.
6. x + y = ?
As the sum of all the internal angles of a quadrilateral = 360
=> (180-x) + (180-y) + (180-z) + (180-w) = 360
So, for knowing the value of x + y, we need the values of both z and w. So, both option 1 and 2 are required simultaneously. Hence, answer will be C.
7.
x20 - x19 = 2 . If you keep solving the RHS and at last put x1 = 3, you'll get the answer as 2^19 i.e option A
I am sure there will be some more logical and easier solution exists.
ashishjha100 SaysPls help......
for first problem of document my expalnation is
Q2:
If 2 different representatives are to be selected at random from a group of 10 employees and if p is the probability that both representatives selected will be women, is p > ?
(1) More than of the 10 employees are women.
(2) The probability that both representatives selected will be men is less than .
OA is E but I think B
Answer will be E
Lets take both statement one by one
First Statement:
More than half are women : lets take women(W)= 6
Now probability = 6C2/10C2= 1/3 i.e
Now lets take W = 7 =>probability = 7C2/10C2= 7/15 i.e
Now lets take W= 8 => probability = 8C2/10C2= 28/45 i.e >
Hence statement 1 is not sufficient to answer
Now lets take statement 2 :
Let number of Men is M
MC2/10C2 M(M-1)/10*9 M(M-1)
The values of satisfying above condition will be M=1,2,3
which in itself will not be sufficient as M=1,2 gives p > and M= 3 gives p
Now if we take both the statements together they also wont be sufficient
Hence answer should be E
Hope I am clear in explaining
I'll try to explain 5,6 and 7 -
5. If vmt 0, is v^2m^3t^4 > 0 ?
There will be a doubt that the expression is less than zero if m is -ve as in that case m^3 will also be negative. v^2 and t^4 will always be +ve.
Option 1 : m > v^2
This means m is a positive value as its greater than v^2 which will definitely be +ve. Hence, v^2m^3t^4 > 0. Sufficient.
Option 2 : m > t^4
This means m is a positive value as its greater than t^4 which will definitely be +ve. Hence, v^2m^3t^4 > 0. Sufficient.
Answer will be D.
6. x + y = ?
As the sum of all the internal angles of a quadrilateral = 360
=> (180-x) + (180-y) + (180-z) + (180-w) = 360
So, for knowing the value of x + y, we need the values of both z and w. So, both option 1 and 2 are required simultaneously. Hence, answer will be C.
7.
x20 x19 = 2 . If you keep solving the RHS and at last put x1 = 3, you'll get the answer as 2^19 i.e option A
I am sure there will be some more logical and easier solution exists.
Dopa your approach is correct but we can use a bit more easier approach for last problem
lets find X2 = 2X1-1=5 , X3 = 2X2-1=9,X4=17
X2-X1= 2^1 ,X3-x2=2^2 , X4-x3 = 2^3
here there is a pattern which we can use to find X20-x19= 2^19
A certain company that sells only cars and trucks reported that revenues from car sales in 1997 were down 11 percent from 1996 and revenues from truck sales in 1997 were up 7 percent from 1996. If total revenues from car sales and truck sales in 1997 were up 1 percent from 1996, what is the ratio of revenue from car sales in 1996 to revenue from truck sales in 1996?
A. 1:2
B. 4:5
C. 1:1
D. 3:2
E. 5:3
The OA is A.
Can some one please solve this one with reasons!
Lets consider 1996 revenue for cars and trucks as 100x & 100y respectively.
It is mentioned that in 1997 the revenue from cars decresed by 11% and that of trucks increased by 7 %....hence, 1997 revenue from cars and trucks will be 89x & 107y
As per the information given in the question, the total revenue has increased by 1 %
Therefore, 89x + 107y = 101/100(100x+100y)
89x + 107y = 101(100x + 100y)
Solving this we get x/y ratio as 1:2. hence the answer is A.
Regards
MSD
Hi Puys,
Please help me understand this one in detail.
I am a little weak in Stats!
Q1. A certain characteristics in a large population has a distribution that is symmetric about the mean m. If 68 percent of the distribution lies within one standard deviation d of the mean, what percent of the distribution is less than m + d ?
A. 16%
B. 32%
C. 48%
D. 84%
E. 92%
Q2. A Cash register in a certain clothing store is the same distance from two dressing rooms in the store. If the distance between the two dressing rooms is 16 feet, which of the following could be the distance between the cash register and either dressing room?
I. 6 feet
II. 12 feet
III. 24 feet
A. I only
B. II only
C. III only
D. I and II only
E. II and III only
**(the answer given for the Q2. does not state an assumption, which i think we would need)
Hi Puys,
Please help me understand this one in detail.
I am a little weak in Stats!
Q1. A certain characteristics in a large population has a distribution that is symmetric about the mean m. If 68 percent of the distribution lies within one standard deviation d of the mean, what percent of the distribution is less than m + d ?
A. 16%
B. 32%
C. 48%
D. 84%
E. 92%
Q2. A Cash register in a certain clothing store is the same distance from two dressing rooms in the store. If the distance between the two dressing rooms is 16 feet, which of the following could be the distance between the cash register and either dressing room?
I. 6 feet
II. 12 feet
III. 24 feet
A. I only
B. II only
C. III only
D. I and II only
E. II and III only
**(the answer given for the Q2. does not state an assumption, which i think we would need)
The given figure is an isosceles triangle with equa sides as x and third side = 16
2x>16 => x>8
Hence E
wats the oa?
thanks
The OA for Q1. is D and Q2. is E.
However, for Q2. why cant all of them be in a straight line when the option I also stands true. The question does not tell us that they are not in a straight line.
Logical??
However, for Q2. why cant all of them be in a straight line when the option I also stands true. The question does not tell us that they are not in a straight line.
Logical??
I am still not getting you ankitgarg20!
What if Dressing Room_________6ft________CashReg________6ft_________DR
Lets Say the Cash Reg is 4 ft cubical?
A single point cubical is more realistic or a 4ft cubical is more realistic?
I am still not getting you ankitgarg20!
What if Dressing Room_________6ft________CashReg________6ft_________DR
Lets Say the Cash Reg is 4 ft cubical?
A single point cubical is more realistic or a 4ft cubical is more realistic?
Hmm.. nice analogy but donot assume things in GMAT. If GMAT wanted I to be the answer they would have mentioned that the cubicle is around 4ft. Also whenever it is said distance between two places it is always from the nearest end of the place than the farthest end.
My answer is with ankitgarg... E
The smallest distance is they are on straight line and hence it must be 8ft.
The farthest distance can be anything... so 12 and 24 fit in the solution.. hence E it must be..
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
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
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.
Hi Thanks Again!!