Answer:
Each person will wash all cars for 0.1875 hours
Explanation:
One student takes time to wash all cars = 12
8 students take time to wash all cars =

So, 8 students together takes 1.5 hours to wash the car
Each person spent hours on washing all cars =

Each person spent hours on washing all cars =0.1875 hours
So, Each person will wash all cars for 0.1875 hours