Stone from the ground:
$s = v_it + \frac{1}{2}at^2$
$h_1 = v_{i1}t - \frac{1}{2}gt^2$
$182.88 - 60.96 = 91.44t - \frac{1}{2}9.81t^2$
$4.905t^2 - 91.44t + 121.92 = 0$
$t = 17.19 \, \text{ sec and } \, 1.44 \, \text{ sec}$
Stone from the top of the tower:
Let t2 = time to wait before dropping the second stone
$h = \frac{1}{2}g(t - t_2)^2$
With t = 17.19 sec
$60.96 = \frac{1}{2}(9.81)(17.19 - t_2)^2$
$t_2 = 13.67 \, \text{ sec}$
With t = 1.44 sec
$60.96 = \frac{1}{2}(32.2)(1.44 - t_2)^2$
$t_2 = -2.08 \, \text{ sec}$ (meaningless)
Use $t_2 = 13.67 \, \text{ sec}$ answer