A) 660
B) 620
C) 680
D) 600
Correct Answer: A
Solution :
\[{{T}_{n}}=\frac{(3+(n-1)\times 2)\left( {{1}^{3}}+{{2}^{3}}+...+{{n}^{3}} \right)}{\left( {{1}^{2}}+{{2}^{2}}+...+{{n}^{2}} \right)}\] \[=\frac{3}{2}n(n+1)=\frac{n(n+1)(n+2)-(n-1)n(n+1)}{2}\] \[\Rightarrow {{S}_{n}}=\frac{n(n+1)(n+2)}{2}\]\[\Rightarrow {{S}_{10}}=660\]You need to login to perform this action.
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