11n>10n+9n ⇒11n−9n>10n ⇒(10+1)n−(10−1)n>10n ⇒{‌nC1.10n−1+‌nC310n−0+‌nC510n−5+......}>10n ⇒2n.10n−1+2{‌nC310n−3+‌nC510n−5+.......}>10n ........(1) For n=5 105+2{‌5C3102+‌5C5}>105 (True) For n=6,7,8,.......100 2n10n−1>10n ⇒2n10n−1+2{‌nC310n−3+‌nC510n−5+........}>10° ⇒11n−9n>10n For n=5,6,7,.......100 For n=4, Inequality (1) is not satisfied ⇒ Inequality does not hold good for N=1,2,3,4 So, required number of elements =96