The graph gives the volume of water, in litres, in a container at time t seconds after the water started to ow out of the container. 50 4o 30 Volume (litres) 20 10 0 10 20 30 40 50 60 Time (t seconds) Using the graph, Work out an estimate for the rate at which the water is owing out of the container when t = 12 You must show your working. litres per second