1.∑r=110r(r−1)(10r)=k×29\displaystyle \sum_{r=1}^{10} r(r-1) \binom{10}{r} = k \times 2^9r=1∑10r(r−1)(r10)=k×29, then kkk is equal to:a.101010b.454545c.909090d.100100100Login to continueOnly logged in users canattempt or see the solution.
