Answer:
[tex]\boxed {\tt 3 \ hours}[/tex]
Step-by-step explanation:
Time can be calculated by dividing the distance by the speed.
[tex]t=\frac{d}{s}[/tex]
where d is the distance and s is the speed.
The distance is 90 miles and the speed is 30 miles per hour.
[tex]d= 90 \ mi \\s= 30 \ mi/hr[/tex]
[tex]t=\frac{90 \ mi}{30 \ mi/hr}[/tex]
Divide. Note that the miles, or mi will cancel each other out.
[tex]t=\frac{90}{30 \ hr}[/tex]
[tex]t= 3 \ hr[/tex]
It will take 3 hours to travel 90 miles at 30 miles per hour.
