1 km away from the town there's a 120 km/h sign, 1/2 km away there is a 60 km/h sign, 1/3 km away there is a 40 km/h sign, 1/4 km away there is a 30 km/h sign, 1/5 km away there is a 24 km/h sign and 1/6 km away there is a 20 km/h sign.

If I travel at the speed limits, How long does it take me to get to the town centre from the 120km/h sign?