The figure shows Tap W, Tap X and an empty tank with a capacity of 87.2 litres. Water flows Tap W at 1.2 litres per minute and from Tap X at 2.6 litres per minute. Tap W was turned on first. Tap X was turned on 3 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 W?