ExamBro
ExamBro
JEE Mains · Maths · STD 11 - 8. sequence and series

माना \(S_{k}=\frac{1+2+3+\ldots+ k }{ k }\) है। यदि \(S _{1}^{2}+ S _{2}^{2}+\ldots+ S _{10}^{2}=\frac{5}{12} A\) है, तो \(A\) बराबर है

  1. A \(283\)
  2. B \(301\)
  3. C \(303\)
  4. D \(156\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(303\)

Step-by-step Solution

Detailed explanation

\({S_k} = \frac{{k + 1}}{2}\) \({\sum\limits_{k = 1}^{10} {\left( {\frac{{k + 1}}{2}} \right)} ^2} = \frac{5}{{12}}A\) \({2^2} + {3^2} + {......11^2} = \frac{{5A}}{3}\) \(\frac{{11 \times 12 \times 23}}{6} - 1 = \frac{{5A}}{3}\) \(505 \times \frac{3}{5} = A\) \(A = 303\)
Same subject
Explore more questions on app
From JEE Mains
Explore more questions on app