Answer:
Speeds of car 1 and car 4 are same.
Explanation:
Speed of an object =
![\frac{\text{Distance traveled}}{\text{Time}}](https://img.qammunity.org/2021/formulas/mathematics/college/1e4pzzbybnxhqfsn16ye6c75msdwanz5i9.png)
For car 1,
Speed of car 1 =
![(350)/(5)](https://img.qammunity.org/2021/formulas/mathematics/college/jsxeohjog8nolyyiap17fxi0iaa7lg57zq.png)
= 70 miles per hour
For car 2,
Speed of car 2 =
= 60 miles per hour
For car 3,
Speed of car 3 =
![(320)/(5)](https://img.qammunity.org/2021/formulas/mathematics/college/i2v6qkaamqkzqvtt45dffta2o57ak168w9.png)
= 64 miles per hour
For car 4,
Speed of car 4 =
![(420)/(6)](https://img.qammunity.org/2021/formulas/mathematics/college/os69y1f153m09omo5qvrzuht3bw5azn2pa.png)
= 70 miles per hour
Therefore, speeds of car 1 and car 4 are same.