3r..............4h...............10 800l
3r..............1h...............x
x=1* 10 800/4= 2700l
3r............1h...........2700l
3r.............3h.............y
y=3*2700/1= 8100l
3r............3h............8100l
5r.............3h..............z
z=5*8100/3
z=5*2700
z=13500l
