1.If ∑r=010(10r+1)⋅10r=11⋅11101010⋅a\sum_{r=0}^{10} \binom{10}{r+1} \cdot 10^{r} = \dfrac{11 \cdot 11^{10}}{1010 \cdot a}∑r=010(r+110)⋅10r=1010⋅a11⋅1110, then aaa is equal toa.151515b.111111c.242424d.202020Login to continueOnly logged in users canattempt or see the solution.
