GRE
Exam
Logical Reasoning
Number Series
1,2,2,4,4,4,4,8,8,8,8,...... what is the 1025th term of the sequence
Read Solution (Total 3)
-
- the series has 1 at 1st place for 1 time, 2 starts from 2nd place for 2 times , 4 starts from 4th place for 4 times and 8 from 8th place for 8 times.... as we go doubling the digits we go 1,2,4,8,16,32,64,128,256,512,1024.... so we know that from 1024th place or term the number will be 1024 which will continue for next 1024 times...so obviously 1025th term which is next to 1024th term will be 1024...
Thank you - 8 years agoHelpfull: Yes(3) No(2)
- The below two answers are almost right but the missed the term 1 which is 1 st number of sequence.So the answer will be 2^9 =512.
- 8 years agoHelpfull: Yes(1) No(0)
- 1024
Here the number of terms are in geometric progression, 1,2,4,8,......
So to find 1025th term, we can take the sum upto 1025 of a geometric series=a[(1-r^n)]/(1-r)
Here a=1, r=2 , So for 'n' terms, 1*[(1-2^n)]/(1-2)=1025, 2^n=1026
As 2^10=1024, so from 1024th terms will be 1024, hence 1025th term will be 1024 - 8 years agoHelpfull: Yes(0) No(2)
GRE Other Question