Elitmus
Exam
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1,2,1,2,2,1,2,2,2,1,2,2,2,2 ,......up to 1239
Find the sum of this numbers.....
Read Solution (Total 6)
-
1,2,1,2,2,1,1,2,2,2,1......
here in this series first we would combine first two terms then next three terms and so on ...
so the resultant series will be
3,5,7,9,11,13,.....
so to calculate the no of terms of the resultant series
let it be n
so it is increasing with a common difference of 1
so the equation will be like n(n+1)/2 -1=1239
By solving this quadratic equation we get n=49
so the sum of this A.P SERIES is 49/2(2*3+(49-1)2)=2499
- 8 years agoHelpfull: Yes(9) No(7)
- ANS SHOULD BE 2429
- 8 years agoHelpfull: Yes(2) No(3)
- 1,2,1,2,2,1,1,2,2,2,1......
here in this series first we would combine first two terms then next three terms and so on ...
so the resultant series will be
3,5,7,9,11,13,.....
so to calculate the no of terms of the resultant series
let it be n
so it is increasing with a common difference of 1
so the equation will be like n(n+1)/2 -1=1239
By solving this quadratic equation we get n=49
so the sum of this A.P SERIES is 3(2^49 -1) - 8 years agoHelpfull: Yes(1) No(6)
- @ rajat- hw did u get the solution of n(n+1)/2-1=1239, as 49...
49 does not satisfy the equation even... - 8 years agoHelpfull: Yes(0) No(0)
- Answer : 1599
- 8 years agoHelpfull: Yes(0) No(0)
- 49/2(2*3+(49-1)2)=2597
- 8 years agoHelpfull: Yes(0) No(1)
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