Answer :
Given:
The speed of the truck is,
[tex]v=100\text{ km/hr}[/tex]The distance is,
[tex]s=900\text{ km}[/tex]The time to drive this distance is,
[tex]t=\frac{s}{d}[/tex]Substituting the values we get,
[tex]\begin{gathered} t=\frac{900}{100} \\ =9\text{ hrs} \end{gathered}[/tex]Hence, the time is 9 hrs.