The figure shows Tap C, Tap D and an empty tank with a capacity of 49.2 litres. Water flows Tap C at 1.8 litres per minute and from Tap D at 3.9 litres per minute. Tap C was turned on first. Tap D was turned on 2 minutes later. The taps were turned off at the same time when the tank was completely filled without overflowing. How much water flowed from Tap C?