You divided cm³ by litres, that's where you went wrong.
The volume of the cilinder is 753982 cm³ which is 753.982 litres
To fill it takes 753.982/0.2 seconds ≈ 3769.9 seconds.
In an hour there are 60*60=3600 seconds, so it takes slightly more than one hour.
But as you can see you were very close. It helps to always write the unit with any number.
