Amanda takes 14 hours to travel 720 km, if she travels 240 km by tow truck and the rest by van. If she travels 320 km by tow truck and the rest by van, she takes 40 minutes more. Find the ratio of the speeds of the tow truck and the van.
- 5 ∶ 3
- 3 ∶ 2
- 2 ∶ 3
- 3 ∶ 5