A thief started his journey at a speed of 60 km/h. After 30 minutes, police started from the same place but at a speed of 80 km/h. How much time (in hours) will the police take to catch the thief?
1
\(\frac {3} {2}\) hours
2
\(\frac {1} {2}\) hours
3
\(\frac {1} {3}\) hours
4
\(\frac {5} {2}\) hours