A variable X takes values 0,0,2,6,12,20, …, n ( n -1) with frequencies ^n C_0,^n C_1,^n C_2,^n C_3,^n C_4,^n C_5, …,^n C_n, respectively. If the mean…

A variable X takes values $\displaystyle 0,0,2,6,12,20, \ldots, \mathrm{n}(\mathrm{n}-1)$ with frequencies $\displaystyle { }^{\mathrm{n}} \mathrm{C}_0,{ }^{\mathrm{n}} \mathrm{C}_1,{ }^{\mathrm{n}} \mathrm{C}_2,{ }^{\mathrm{n}} \mathrm{C}_3,{ }^{\mathrm{n}} \mathrm{C}_4,{ }^{\mathrm{n}} \mathrm{C}_5, \ldots,{ }^{\mathrm{n}} \mathrm{C}_{\mathrm{n}}$, respectively. If the mean of this data is $\displaystyle 60$ , then its median is :