A variable X takes values 0,0,2,6,12,20, . . . n(n−1)n(n-1)n(n−1) with frequencies nC0,nC1,nC2,nC3,nC4{}^n C_0, {}^n C_1, {}^n C_2, {}^n C_3, {}^n C_4nC0,nC1,nC2,nC3,nC4, nC5,…nCn{}^n C_5, \ldots {}^n C_nnC5,…nCn, respectively. If the mean of this data is 60 , then its median is:
56
42
72
90