Answer:
b. 60
Explanation:
We have been given a formula
, where x represents the number of small vehicles and y represents the number of larger vehicles.
To find the number of small vehicles, we will substitute
in the given equation as:
![5x+10(50)=800](https://img.qammunity.org/2020/formulas/mathematics/high-school/6722mbg0exwir4xbil3jy4ekeac5k38ydl.png)
![5x+500=800](https://img.qammunity.org/2020/formulas/mathematics/high-school/z0m4eqp5bn8dl79wyzn23so36kgyx6okuv.png)
![5x+500-500=800-500](https://img.qammunity.org/2020/formulas/mathematics/high-school/3q1cuoddnnquh18z8ug559d7z03kyxtljz.png)
![5x=300](https://img.qammunity.org/2020/formulas/mathematics/high-school/wbzp05id3b15dqagv5jtapiar0cl0jcch3.png)
![(5x)/(5)=(300)/(5)](https://img.qammunity.org/2020/formulas/mathematics/high-school/xsscl4m7rd4slgcicfpqwhgw6hl9x5z50z.png)
![x=60](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h2chsnli8sn7zxwmvysbaqyqk3bphoh1h3.png)
Therefore, 60 small vehicles were washed in total and option 'b' is the correct choice.