Answer:
[tex]\textsf{1)} \quad t=\dfrac{48}{r}[/tex]
[tex]\textsf{2)} \quad \sf 2.4\:hours=2\:hours\:24\:minutes[/tex]
Step-by-step explanation:
[tex]\boxed{\sf Time=\dfrac{Distance}{Speed}}[/tex]
Given:
Substitute the given values into the formula:
[tex]\implies t=\dfrac{48}{r}[/tex]
Substitute r = 20 km/h into the derived equation from part 1 and solve for t:
[tex]\implies t=\dfrac{48}{20}=2.4\: \sf hours[/tex]
Note: 2.4 hours = 2 hours 24 minutes