insanejuxtapose SaysYou just missed it! The answer is not B.. but C.. u did consider 371 but you did not take another no into consideration..! think.. !
Ha . Missed 370.
Ha . Missed 370.
Sriram_Avadhani SaysHa . Missed 370.
Right ! .. Way to go.. Post questions if you got a few..
Can somebody pls solve the following question :
A series in which any term is the sum of the preceding terms is fibonacci series. The first 2 terms are given initially and together they determine the series. If the difference of the squares of the 9th and 8th term of the series is 715 then what is the 12th term >?
Options
157
142
144
cant be determined.
By hit n trial i can get the number.. but can anybody suggest a method to do this problem ?
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
I want to know How many times Gmat conduct in a year ? and where did i find the notifications and application?
seshukumar SaysI want to know How many times Gmat conduct in a year ? and where did i find the notifications and application?
mba.com
or try wikipedia.org for gmat
Can somebody pls solve the following question :
A series in which any term is the sum of the preceding terms is fibonacci series. The first 2 terms are given initially and together they determine the series. If the difference of the squares of the 9th and 8th term of the series is 715 then what is the 12th term >?
Options
157
142
144
cant be determined.
By hit n trial i can get the number.. but can anybody suggest a method to do this problem ?
is this something that could be on the GMAT?? :crazyeye:
well was trying to break my head to think of a way to solve this.. (i suck at math btw)
made some progress but cant go all the way.. maybe some one can expand on this or correct me whr i went wrong.. ehre goes..
Eg. of a Fibo Series --> 0, 1, 1, 2, 3, 5, 8, 13, 21....
t1,t2,t3,t4,t5,t6,t7, t8, t9,....t12...
in our prob here, let x, y be the starting 2 nos..(x=0 and y=1 in this case)
any term in the series can be represented as
Tn=(x+(n-2)y)
difference of the squares of the 9th and 8th term of the series is 715
==> (x+7y)^2 - (x+6y)^2 = 715
(hopefully) so far so good... reducing the above, we get
y(2x+13y)=715
whew... now wat??? btw T12 = (x+10y)
so we get y(x+10y + x+ 3y)=715
y(T12 + T5)=715
now wat??
i know im crazy.. this is worse than my +2 boards!
??:
Can somebody pls solve the following question :
A series in which any term is the sum of the preceding terms is fibonacci series. The first 2 terms are given initially and together they determine the series. If the difference of the squares of the 9th and 8th term of the series is 715 then what is the 12th term >?
Options
157
142
144
cant be determined.
By hit n trial i can get the number.. but can anybody suggest a method to do this problem ?
Hi,
I think we may be missing out on something here !! Question says "then what is the 12th term >?" .. So is it asking specifically that what is the 12th term or is it asking " What is the 12th term greater than..?" Could you check your source of the question to make sure whether the ">" sign is a part of the question or not ??
A----------B---------C----------DI
Is
CD > BC ?
(1) AD = 20
(2) AB = CD
A Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D EACH Statement ALONE is sufficient.
E Statements (1) and (2) TOGETHER are NOT sufficient.
I think the answer is E
Hi,
I think we may be missing out on something here !! Question says "then what is the 12th term >?" .. So is it asking specifically that what is the 12th term or is it asking " What is the 12th term greater than..?" Could you check your source of the question to make sure whether the ">" sign is a part of the question or not ??
Guys,
The answer would be 144, just see this. The fibonacci series starts with 1 not 0.
So the series goes as
1,1,2,3,5,8,13,21,34,55,89,144
The 8th term is 21(square is 441) and the 9th term is 34(square is 1156), their difference being 715. Thus, 144 being the 12th term.
Guys,
The answer would be 144, just see this. The fibonacci series starts with 1 not 0.
So the series goes as
1,1,2,3,5,8,13,21,34,55,89,144
The 8th term is 21(square is 441) and the 9th term is 34(square is 1156), their difference being 715. Thus, 144 being the 12th term.
Yup.. fair enougth.. seems to make sense.. however, its pure hit and trial isnt it..? What if the series started with some number other than 1? You started with 1 and luckily it coincided.. so basically there's no particular method to get around the question..?
Rule of Thumb: If no 2 starting numbers are given for Fibonacci series, it starts with 1,1 to give the third no. as 2...hope it will help
Hi,
Can someone please help me solve these qusetions? I am sorry if these have already been posted before. :P
Q1. For every positive even integer n, f(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor h(100) + 1, then p is
A. 1/8
B. 1/4
C. 3/8
D. 1/2
E. 3/4
q3. Car A & Car B travel around a circular park with an area of 1256 sq. miles. Both cars leave from the same point, Car A travels counter-clockwise at 60 miles/hr. Car B travels 20 min after Car A, travels clockwise at 40 miles/hr. Approx how long does it take for the cars to meet after car A starts? Use 3.14 for Pie.
A. 63 min
B. 75 min
C. 83 min
D. 126 min
E. 188 min
q4. It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each technician working at the same rate. If 6 tech. start to build at 11 AM, and 1 tech per hour beginning at 5 PM, at what time will the server be complete.
A. 6:40 PM
B. 7:00 PM
c. 7:20 PM
D. 7:40 PM
E. 8:00 PM
q5. The first 3 terms of a sequence are 2,7,22. Each term, after the first, is obtained by multiplying the previous term by 3 and then adding 1. If the sequence continues to expand, what will be the sum of the tens and the unit digits of the thirty fifth term in the sequence.
A. 2
B. 4
C. 7
D. 9
E. 13
q6. A salesman's income consists of 2 components: C & R. R= $350/week. His goal is to make enough C to average $500 in total income per week. Over the past 5 weeks, his weekly income totals have been $406, $413, $420, $436, $395. By approx what percent does he need to raise his avg. weekly C, over the next 2 weeks, to raise his avg, weekly income to $500 over the 7-week period.
A. 74%
B. 88%
C. 176%
D. 276%
E. 470%
Thanks, :)
Shipra
Can someone please help me solve these qusetions? I am sorry if these have already been posted before. :P
Q1. For every positive even integer n, f(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor h(100) + 1, then p is
- between 2 & 10
- between 10 & 20
- between 20 & 30
- between 30 & 40
- >40
A. 1/8
B. 1/4
C. 3/8
D. 1/2
E. 3/4
q3. Car A & Car B travel around a circular park with an area of 1256 sq. miles. Both cars leave from the same point, Car A travels counter-clockwise at 60 miles/hr. Car B travels 20 min after Car A, travels clockwise at 40 miles/hr. Approx how long does it take for the cars to meet after car A starts? Use 3.14 for Pie.
A. 63 min
B. 75 min
C. 83 min
D. 126 min
E. 188 min
q4. It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each technician working at the same rate. If 6 tech. start to build at 11 AM, and 1 tech per hour beginning at 5 PM, at what time will the server be complete.
A. 6:40 PM
B. 7:00 PM
c. 7:20 PM
D. 7:40 PM
E. 8:00 PM
q5. The first 3 terms of a sequence are 2,7,22. Each term, after the first, is obtained by multiplying the previous term by 3 and then adding 1. If the sequence continues to expand, what will be the sum of the tens and the unit digits of the thirty fifth term in the sequence.
A. 2
B. 4
C. 7
D. 9
E. 13
q6. A salesman's income consists of 2 components: C & R. R= $350/week. His goal is to make enough C to average $500 in total income per week. Over the past 5 weeks, his weekly income totals have been $406, $413, $420, $436, $395. By approx what percent does he need to raise his avg. weekly C, over the next 2 weeks, to raise his avg, weekly income to $500 over the 7-week period.
A. 74%
B. 88%
C. 176%
D. 276%
E. 470%
Thanks, :)
Shipra
Hi,
q2. A circle is centered on origin in the xy-plane. Pt(A,B) is randomly selected inside of the circle. What is the probability that A>B>0?
A. 1/8
B. 1/4
C. 3/8
D. 1/2
E. 3/4
Lets solve this by POE. For A>B>0, the point has to be in the first quadrant. The probability that the point lies in the first quadrant is 1/4. Hence remove all choices greater than 1/4. C, D and E are out. This leaves us with A and B. Now, even within the first quadrant, not all points are A>B. Hence 1/4 is also out.
Hence the answer is A.
Vikram.
q3. Car A & Car B travel around a circular park with an area of 1256 sq. miles. Both cars leave from the same point, Car A travels counter-clockwise at 60 miles/hr. Car B travels 20 min after Car A, travels clockwise at 40 miles/hr. Approx how long does it take for the cars to meet after car A starts? Use 3.14 for Pie.
A. 63 min
B. 75 min
C. 83 min
D. 126 min
E. 188 min
Alrite, this one took some time....
The area is 1256sq.mi and hence once u do the math, u will get the radius to be 20miles. This will make the circumfrance to be 125.6 miles. Now, car A has travelled for 20 min before Car B started.
In 20 min, car A would have travelled (d = s*t) 60 * (1/3) = 20 miles. Deduct these 20 miles from our calculations as we dont need to be worried about this anymore. Hence, the total distance that we require is 105.6 miles.
Now car A travels at 60mph and car B travels at 40mph. Hence the combined velocity is 100mph. The question can now be rephrased as "How long does it take a car travelling at 100mph to cover a distance of 105.6 miles?"
t = d/s = 105.6/100 = 1.056 hours = 63.3 minutes.
Answer is A.
Vikram
EDIT:: GRRR... I didnt add the first 20 mins that we "omitted" to the final account. So, it should be 63.3 + 20 = 83.3. So, the correct answer is C. 😞
q4. It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each technician working at the same rate. If 6 tech. start to build at 11 AM, and 1 tech per hour beginning at 5 PM, at what time will the server be complete.
A. 6:40 PM
B. 7:00 PM
c. 7:20 PM
D. 7:40 PM
E. 8:00 PM
Just to clarify, I believe the question should be 1 tech is added per hour after 5pm..
6 guys -> 10 hours. So, 6 guys do 1/10 th of the job in 1 hour.
So, 1 tech does 1/60 th job in 1 hour.
Between 11am and 5pm, (1/60)*6*6 = 36/60 of the job gets completed. (job completed by 1 person per hour * no of people * no of hours).
At 5pm, one tech would have been added. Hence at the end of 6pm,
(36/60) + (7/60) of the job would have been completed.
At 6pm, one more techs have been added. Hence at the end of 7pm,
(36/60) + (7/60) + (8/60) of the job has been completed. Now quickly adding them up we get 51/60. So, 9/60 of the job is left.
At 7pm we get 1 more techs. So, we totally have 9 techs with us who are capable of doing 9 * 1/60 of the job in 1 hour. Guess what, we have 9/60 of the job left. Hence, the job would get completed at 8pm.
Answer is E.
Vikram.
q5. The first 3 terms of a sequence are 2,7,22. Each term, after the first, is obtained by multiplying the previous term by 3 and then adding 1. If the sequence continues to expand, what will be the sum of the tens and the unit digits of the thirty fifth term in the sequence.
A. 2
B. 4
C. 7
D. 9
E. 13
The quickest way to solve this would be to continue the series a little more.. Expanding the given series we get,
2, 7, 22, 67, 202, 607, 1822 ....
Adding the units and tens digits of the numbers in the above series we get,
2, 7, 4, 13, 2, 7, 4....
U can immediately see the repetitive pattern. The numbers are repeating every 4th time. Hence 35%4 = 3. The third number in the addition series is 4.
Hence the answer is B.
Vikram.
Q1. For every positive even integer n, f(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor h(100) + 1, then p is
- between 2 & 10
- between 10 & 20
- between 20 & 30
- between 30 & 40
- >40
Again, the question should probably read f(100)+1, else it wouldnt make sense!
Now since f(n) begins with the number 2, we know that there can be no common factors between f(100) and f(100)+1.
Since f(n) is the product of all positive even integers, f(100) would be,
2*4*6*8*.....*48*50*52*54......*100. Now, by our previous assertion, there can be no common factors between f(100) and f(100) + 1. However, f(100) would be divisible by all the even numbers in the set and all the odd numbers less than 50 - This argument will be valid because the odd number can be multiplied by 2 and still denote an even no in the set. Eg. 7 * 2 = 14 which is a part of the set. However 51*2 = 102 is NOT a part of the set!
Hence, the factor for f(100)+1, whatever it may be HAS to be above 50. This corresponds to the last choice >40.
Hence the answer is E.
I am not too sure abt this question. The explanation could be flawed!
Hi,
Can someone please help me solve these qusetions? I am sorry if these have already been posted before. :P
Q1. For every positive even integer n, f(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor h(100) + 1, then p isq2. A circle is centered on origin in the xy-plane. Pt(A,B) is randomly selected inside of the circle. What is the probability that A>B>0?
- between 2 & 10
- between 10 & 20
- between 20 & 30
- between 30 & 40
- >40
A. 1/8
B. 1/4
C. 3/8
D. 1/2
E. 3/4
q3. Car A & Car B travel around a circular park with an area of 1256 sq. miles. Both cars leave from the same point, Car A travels counter-clockwise at 60 miles/hr. Car B travels 20 min after Car A, travels clockwise at 40 miles/hr. Approx how long does it take for the cars to meet after car A starts? Use 3.14 for Pie.
A. 63 min
B. 75 min
C. 83 min
D. 126 min
E. 188 min
q4. It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each technician working at the same rate. If 6 tech. start to build at 11 AM, and 1 tech per hour beginning at 5 PM, at what time will the server be complete.
A. 6:40 PM
B. 7:00 PM
c. 7:20 PM
D. 7:40 PM
E. 8:00 PM
q5. The first 3 terms of a sequence are 2,7,22. Each term, after the first, is obtained by multiplying the previous term by 3 and then adding 1. If the sequence continues to expand, what will be the sum of the tens and the unit digits of the thirty fifth term in the sequence.
A. 2
B. 4
C. 7
D. 9
E. 13
q6. A salesman's income consists of 2 components: C & R. R= $350/week. His goal is to make enough C to average $500 in total income per week. Over the past 5 weeks, his weekly income totals have been $406, $413, $420, $436, $395. By approx what percent does he need to raise his avg. weekly C, over the next 2 weeks, to raise his avg, weekly income to $500 over the 7-week period.
A. 74%
B. 88%
C. 176%
D. 276%
E. 470%
Thanks, :)
Shipra
Q.1:
see, f(10)+1 = 3841.... so the smallest prime factor is 23
if u go on to do a lil bit more calculations, u will find tht f(12)+1 = 46081...the smallest prime factor is 29....so u can comfortably assume that f(100)+1 will have a prime factor greater than 40....answer is E...
Q.2
since the centre of the circle is on the origin, u will have the circle divided equally in all the 4 quadrants....
the probability that both A and B >0 is 1/4 thus...(cuz this condition is satisfied only in the first quadrant)
now the probability tht A>B in first quadrant needs to be calculated, which will again be less than 1...thus, the final answer will be less than 1/4...the only answer less than 1/4 is 1/8...hence, answer is A..
Q.3
area = 1256...hence, radius = 20...hence, circumference = 125.6
since car B leaves 20 mins after car A leaves, after 1hr20 mins, carB will travel 40 miles in clockwise direction and car A will travel 80 miles in anti-clockwise direction...thus, after 1 hr 20 mins, both cars will be 5.6 miles apart...hence, it would take a little over 80 mins for both cars to meet..answer is C...
Q.4
6 tech take 10 hrs to complete the work
1 tech takes 60 hrs to complete work
..frm 11am till 5 pm, 6 tech will complete 6/10th of the work...now 1 tech is added...
7 tech will take 60/7 hrs to complete work..so they will complete 7/60th part of work in 1 hr...
now after 1 hr, one more tech is added..
8 tech will take 60/8 hrs to complete work..so they will complete 8/60th part of work in 1 hr..goin by this, we have
6/10 + 7/60 + 8/60 + 9/60 = 1
thus, work will be completed by 8 pm... answer is E...
Q.5
let us define f(n) = sum of units and tens digits of n
so,
f(1) = sum of units and tens digit of 2 = 2
f(2) = sum of units and tens digit of 7 = 7
f(3) = sum of units and tens digit of 22 = 4
f(4) = sum of units and tens digit of 67 = 13
f(5) = sum of units and tens digit of 202 = 2
f(6) = sum of units and tens digit of 607 = 7
f(7) = sum of units and tens digit of 1822 = 4
.
.
.
.
u can see there is a pattern being formed - 2,7,4,13...which means, cyclicity of 4....hence,
f(35) will yield a sum of units and tens digit of 4...answer is B..
Q.6
the goal is the salesman should have his total income after 7 weeks = 3500
now, in the first five weeks, his total income = 2070..so in the next 2 weeks, his income should be 1430 to reach his goal...
average weekly C = $150..and his avg. weekly needed to reach his goal = 365...so he needs to raise his C by $115 per week....now, 15*8 = 120...hence, the approx percent increase = 176%...answer is C...
hope it helps...
Hi Guys,
Vikram and Ajay, thanks a ton for your answers. Both of you got most of the answers correct! 😃 i need to learn a lot :P
here are the correct answers
Q1. E
Q2. A
Q3. C
Q4. E
Q5. B
Q6. E
but i have a doubt, perhaps a silly one, in Q2.
the probability of (a,b) being in Quadrant-I = 1/4
however, after that, for a,b in Quad-I , aren't there 3 possibilities...
a>b
a=b
ab = 1/3 (and not 1/2)
and the final answer becomes 1/12 ( instead of 1/
. Now I understand that in this question, 1/12 is not an option, but if it were...what would be the correct answer?
thanks again,
Shipra
Here's one more...
Ron gets into an elevator at 11th floor and starts going up at the speed of 53 floors/minute. Ally gets into another elevator at the 51st floor which starts coming down at a rate of 63 floors/minute. At which floor will their paths cros??
I am sorry but I dont remember the answer options (this was in one of the Kaplan tests I took)
More interested in the method really, since I remember I couldnt match any of the options.
thanks,
Shipra
Ron gets into an elevator at 11th floor and starts going up at the speed of 53 floors/minute. Ally gets into another elevator at the 51st floor which starts coming down at a rate of 63 floors/minute. At which floor will their paths cros??
I am sorry but I dont remember the answer options (this was in one of the Kaplan tests I took)
More interested in the method really, since I remember I couldnt match any of the options.
thanks,
Shipra