Step 1: Speed is defined as the rate of covering a distance, mathematically it is given by
[tex]\begin{gathered} S\text{peed}=\frac{\text{distance}}{\text{time}} \\ S=\frac{d}{t} \end{gathered}[/tex]Step 2: Make the time (t) of the subject in the above speed formula
[tex]t=\frac{d}{S}[/tex]Step 3: Given the distance covered and the average speed used during the trip as
[tex]\begin{gathered} S=60\text{miles per hour} \\ d=1260\text{ miles} \end{gathered}[/tex]Step 4: Substitute the values for distance and speed in the time formula in step 2
[tex]\begin{gathered} t=\frac{d}{S} \\ t=\frac{1260}{60} \\ t=21\text{ hours} \end{gathered}[/tex]Hence, Santa's trip will take up to 21 hours