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What is the sum of squares of first 20 natural numbers? a)2870 b)2000 c)5650 d)44100
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- formula for this is :
S= {n(n+1)(2n+1)}/6
here n=20
so S={20*21*41}/6
=10*7*41 (after cancelations)
so the result must end with 70.
so the answer is a)2870 - 10 years agoHelpfull: Yes(14) No(0)
- formula is n(n+1)(2n+1)/6
and n=20 here
so ans is 2870 - 10 years agoHelpfull: Yes(1) No(0)
- sum of n squares can be found as s(n)=((n)*(n+1)*(2n+1))/6
on substituting 20 we get, (20*21*41)/6=2870 - 10 years agoHelpfull: Yes(1) No(0)
- n(n+1)(2n+1)/6
20*21*41/6= 2870 - 10 years agoHelpfull: Yes(1) No(0)
- @ashish kamble ..there is no nothing available here in the site ,please tell provide here the exact link where i should register.
- 10 years agoHelpfull: Yes(0) No(0)
- 1^2+2^2+3^2+.....upto n terms = n(n+1)(2n+1)/6..
20*21*41/6=2870 - 10 years agoHelpfull: Yes(0) No(0)
- n (n+1) (2n+1)/6=20*21*41/6=2870
- 10 years agoHelpfull: Yes(0) No(0)
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