Answer:
t = 7.5 s
Step-by-step explanation:
As we know that the average speed between two lights is given as
![v = 24 mph](https://img.qammunity.org/2020/formulas/physics/high-school/9rd1ji8ny2jpe3d5ugcmrfv23y6t6g53vg.png)
here we know that
![v = 24 * (1602 m)/(3600 s)](https://img.qammunity.org/2020/formulas/physics/high-school/f8q6gqny9ux5ythpypgwq9hhc9mi9ear28.png)
![v = 10.68 m/s](https://img.qammunity.org/2020/formulas/physics/high-school/72acw56b6719pnb022cl2d5ilrruwtmfqg.png)
now the distance between two lights is 80 m
so here if all the cars are moving continuously between two lights then the time delay between two lights is given as
![t = (L)/(v)](https://img.qammunity.org/2020/formulas/physics/middle-school/n0zk2r1af6heksv5mk89ksqviyzdz65031.png)
![t = (80)/(10.68)](https://img.qammunity.org/2020/formulas/physics/high-school/2zjw1equy16g1yrcywhxbjw42mmxv6cwra.png)
![t = 7.5 s](https://img.qammunity.org/2020/formulas/physics/high-school/zjytchz98xazjea85xa3ah0o0yuynxj6kk.png)