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Value of `sum_(k=1)^(oo) sum_(r=0)^(k) (1)/(3^(k)) (""^(k)C_(r))` isA. `2/3`B. `4/3`C. `2`D. 1 |
Answer» Correct Answer - C `underset(k=1)overset(oo)sumunderset(r=0)overset(k)sum(1)/(3^(4))(.^(k)C_(r))=underset(k=1)overset(oo)sum(1/(3^(k))(underset(k=0)overset(k)sum.^(k)C_(r)))` `= underset(k=1)overset(oo)sum((2^(k))/(3^(k)))` `= 2/3+(2/3)^(2)+"....."oo` `= (2//3)/(1-2/3) = 2` |
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