1.Set of values of rrr for which (18r−2)+2(18r−1)+(18r)≥(2013)\binom{18}{r-2} + 2\binom{18}{r-1} + \binom{18}{r} \ge \binom{20}{13}(r−218)+2(r−118)+(r18)≥(1320) contains:a.444 elementsb.555 elementsc.777 elementsd.101010 elementsLogin to continueOnly logged in users canattempt or see the solution.
