Goldman Sachs Interview Question for Software Engineer / Developers






Comment hidden because of low score. Click to expand.
10
of 10 vote

The numbers given are the first numbers that appear after the decimal point when converted from these fractions: 1/2, 2/3, 3/4, 4/5, 5/6, 6/7, 7/8, 8/9, and 9/10.

http://www.puzz.com/1001/series17.htm

- YetAnotherCoder October 02, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

Kew!

- Anonymous October 09, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

Ans :9

- vas November 15, 2007 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

Any explanation for 9?

- Anonymous November 15, 2007 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

hi,
i think its 9:

5 6 7 8 8 8 8 8... if you observe the difference between the 1st no and last no is 3, then the second and the second from last is 2, and so on ... until it becones 8-8 = 0.

So if we need to preserve tht order, i guess a 9 shud be placed as the next number.

- Venkat November 16, 2007 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 votes

I think the number must be 8 again, becoz your observation till 8-8=0 is correct till 8-8=0 an symmetry is there. So to this series if I add and 8 again then the difference between the 1st no and last no is 3, then the second and the second from last is 2, and so on ... until it becomes 8-8 = 0, and one middle number can be any thing(in this case it is 8).

- Ravi July 23, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

Not enough data. Or the question is ambiguous. If it is 9, then the question should be "What is the FIRST and LAST number in this give series so far?".. which in this case will be 5 and 9 to preserve 4, 3, 2, 1, 0. But it can also be 4 and 8 to preserver 4, 3, 2, 1, 0. So the answer can also be 8. These questions are to see how strong your observation can be.. there isn't any right answer. If you just say 9 by itself, it doesn't make sense because it cannot preserve the order -> 5 6 7 8 8 8 8 8 9:

9-5 = 4
8-6 = 2
8-7 = 1
8-8 = 0
8

there is no sequence. 8, 0, 1, 2, 4

- Anonymous November 16, 2007 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 2 vote

7

the first three differences were 1. (5 6 7 8)
the next three differences were 0. (8 8 8 8)
so the next three differences should be -1. (7 6 5 4)

- Anonymous January 14, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

Why it cannot be 9 8 7 6

- Ravi July 23, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 votes

It is min(n, 8) => 8

Or it could be anything as long as you can explain.

This type of questions are dumb.

- Anonymous June 22, 2012 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

if v add the 1st and the 4th no. the result is =5+8=13
and then add 2nd and 5th no. the result is=6+8=14
now keep adding the next no. with 6th no. result is =7+8=15
then 8+8=16
to continue the counting we add 8+x=17
so x=17-8=9
so next no. of series will b 9
5 6 7 8 8 8 8 _   = 5 6 7 8 8 8 8 9

- gaurav s. January 18, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

Dear gaurav your idea is excellent , but u dont u think that you should use whole string

to use whole series 5678 8888 we should add 1st and the 5th no. the result is =5+8=13
and then add 2nd and 6th no. the result is=6+8=14
now keep adding the next no. with 7th no. result is =7+8=15
then last 8+8=16

so if we want any number here it should be 9 and if we ask to add next number too then it will be 10

- Ravi July 23, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

if v add the 1st and the 5th no. the result is =5+8=13
and then add 2nd and 6th no. the result is=6+8=14
now keep adding the next no. with 7th no. result is =7+8=15
then 8+8=16
to continue the counting we add 8+x=17
so x=17-8=9
so next no. of series will b 9
5 6 7 8 8 8 8 8 _   = 5 6 7 8 8 8 8 8 9

- gaurav . s . January 18, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

I would say 8. Apply Occam's razor ... all things being equal, the simplest solution is the best.
You could argue that the series stabilizes at at 8.

- Ash February 23, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

you can see the pattern visually as...

1  2  3  4-> 4  4  4  4

(((5 6 7 8-> 8 8 8 8

- cbreezy March 12, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

I would do expected value for this brain teaser since it is very subjective to say which number comes first. Which means you would have to assume the same probability for each number. The sum of all numbers is 58. You divide it by 8 assuming that each of the has the probability of 1/8 (8 data entries). You will get 7.25 as your final answer. I don't think you can go wrong with this answer.

- Matt June 06, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

1. Series adding 4 consecutive numbers -
26,29,31,32,32

2. Step 1 forms an AP of d=-1
3,2,1,0,-1
Next no should be -1 in this AP. This implies that next no in series in step one would be 31.

3. 8+8+8+x=31
<=> x=7

so next no will be 7
5 6 7 8 8 8 8 8 7 ...

- pk July 29, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

answer is 9. The numbers given are the first numbers that appear after the decimal point when converted from these fractions: 1/2, 2/3, 3/4, 4/5, 5/6, 6/7, 7/8, 8/9, and 9/10.

- pj August 30, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

i like this idea

- Anonymous September 15, 2008 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

wtf haha. there is no one answer to this question.

- jesuscheung September 17, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

(5 6 7 8) (8 8 8 8) (8 9 10 11) (11 11 11 11) ( ....

in each adjacent brackets of 4 numbers the difference between the first number in the first bracket and last number in the second bracket is 3, the difference for the second number is 2, then 1 and 0 so forth

- dd October 24, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

answer could be -1

- sonu singh October 29, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

5 6 7 8 8 8 8 8 ?
I4- I1 = 8 - 5 = 3
I5- I2 = 8 - 6 = 2
I6 -I3 = 8 -7 = 1
I7 - I4 = X - 8 = 0;
X= 8

- Jackson Zhou November 01, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

5 6 7 8 8(t1+3) 8(t2+2) 8(t3+1) 8(t4+0) 11(t5+3) 10(t6+2) 9(t7+1) 8(t8+0)...............

- Debasis Samanta June 08, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

it is right...........

- Soma June 08, 2009 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 votes

it is right...........

- Amit June 11, 2009 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 votes

f(1)=5
f(2)=6
f(3)=7
f(4)=8
f(5)=8
f(6)=8
f(7)=8
f(8)=8
f(9)=13
f(10)=14
f(11)=15
f(12)=16
f(13)=16
f(14)=16
f(15)=16
f(16)=16


???????

Can this not be a possible solution??

MY answer is 13

- Geekenized August 02, 2009 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 vote

f(1)=5
f(2)=6
f(3)=7
f(4)=8
f(5)=8
f(6)=8
f(7)=8
f(8)=8
f(9)=13
f(10)=14
f(11)=15
f(12)=16
f(13)=16
f(14)=16
f(15)=16
f(16)=16


???????

Can this not be a possible solution??

MY answer is 13

- Geekenized August 02, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

f(1)=5
f(2)=6
f(3)=7
f(4)=8
f(5)=8
f(6)=8
f(7)=8
f(8)=8
f(9)=13
f(10)=14
f(11)=15
f(12)=16
f(13)=16
f(14)=16
f(15)=16
f(16)=16


???????

Can this not be a possible solution??

MY answer is 13

- Geekenized August 02, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

i agree with Venkat and Debasis Samanta's solution , there approach is correct. rest of the people are just repeating the same thing.

- googler August 13, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

@Geekenized
how de hell did u get 13??

- varsha September 08, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

@Geekenized
how de hell did u get 13??

- varsha September 08, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

@Geekenized
how de hell did u get 13??

- varsha September 08, 2009 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

7

- abc August 20, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

679868? Can someone help me in missing number

- jasdeep March 31, 2014 | Flag Reply
Comment hidden because of low score. Click to expand.
-1
of 1 vote

series - 5 6 7 8 8 8 8 8 ........

if we observe there are four different AP series which have different d = 3,2,1,0.

first 5 8 ... difference 3
second 6 8 .... difference 2
third 7 8 ... difference 1
fourth 8 8 ... difference 0

so next step should be 11

5 6 7 8 8 8 8 8 11 10 9 8 .............

any comments

- Anonymous April 06, 2008 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

2 numbers will always form an AP.

- coderBon September 19, 2012 | Flag


Add a Comment
Name:

Writing Code? Surround your code with {{{ and }}} to preserve whitespace.

Books

is a comprehensive book on getting a job at a top tech company, while focuses on dev interviews and does this for PMs.

Learn More

Videos

CareerCup's interview videos give you a real-life look at technical interviews. In these unscripted videos, watch how other candidates handle tough questions and how the interviewer thinks about their performance.

Learn More

Resume Review

Most engineers make critical mistakes on their resumes -- we can fix your resume with our custom resume review service. And, we use fellow engineers as our resume reviewers, so you can be sure that we "get" what you're saying.

Learn More

Mock Interviews

Our Mock Interviews will be conducted "in character" just like a real interview, and can focus on whatever topics you want. All our interviewers have worked for Microsoft, Google or Amazon, you know you'll get a true-to-life experience.

Learn More