TCS
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Numerical Ability
Age Problem
What is the sum of the following series?
7 + 26 + 63 + 124 + .... + 999
a)3014 b) 3013 c) 3015 d) None of these
Read Solution (Total 3)
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- sum of cubes is (n*(n+1)/2)^2....now n is 10 and give series is n^3-1...whr n is 2,3,,....10 and 1 is missing...in this sequence... so...finding the entire sum and subtracting 1 from this sequence gives sum of n^3....finally we need to subtract 9 because sequence is sigma(n^3-1).... ans is 3015
- 11 years agoHelpfull: Yes(19) No(4)
- 7+26+63+124+....+999=n^3-1
here n=10.
Sumation Sn= {10(10+1)/2}-n= 3015
Ans= c) 3015 - 11 years agoHelpfull: Yes(15) No(7)
- sum of cube of natural number
that is n=10
& sum=3025-10-1 (start from 2^3)
ANS= 3014
- 11 years agoHelpfull: Yes(5) No(10)
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