A stone falls freely under gravity. It covers distances $h_1,h_2$ and $h_3$ in the first $5\text{seconds}$, the next $5\text{seconds}$ and the next $5\text{seconds}$ respectively. The relation between $h_1,h_2$ and $h_3$ is:

For a body falling from rest, the distance covered in successive equal time intervals follows Galileo's Law of Odd Numbers ($1:3:5:\mathrm{7...}$).Distance in first $5\text{s}$:
$$h_1=\frac{1}{2}g(5{)}^2=12.5g$$
Distance in first $10\text{s}$ ($S_2$):
$$S_2=\frac{1}{2}g(10{)}^2=50g$$
Distance in the next $5\text{s}$ ($h_2$):
$$h_2=S_2-h_1=50g-12.5g=37.5g=3h_1$$
Distance in first $15\text{s}$ ($S_3$):
$$S_3=\frac{1}{2}g(15{)}^2=112.5g$$
Distance in the next $5\text{s}$ ($h_3$):
$$h_3=S_3-S_2=112.5g-50g=62.5g=5h_1$$
Thus, $h_1=\frac{h_2}{3}=\frac{h_3}{5}$.