Solution:
Speed is expressed as
[tex]\text{speed = }\frac{dis\tan ce\text{ covered}}{time\text{ taken}}[/tex]
Given that Thiyo traveled 420 miles at 56 mi/h, let t represent the number of hour he drove.
Thus,
[tex]56\text{ mi/h = }\frac{420\text{ miles}}{t}[/tex]
Make t the subject of the formula.
[tex]\begin{gathered} 56\text{ mi/h = }\frac{420\text{ miles}}{t} \\ \text{Multiply through by t} \\ t(56\text{ mi/h) = t(}\frac{420\text{ miles}}{t}) \\ 56t=420 \\ \text{divide both sides by the coefficient of t, which is 56.} \\ \text{thus, } \\ \frac{56t}{56}=\frac{420}{56} \\ \Rightarrow t=7.5\text{ hours} \end{gathered}[/tex]
Hence, Thiyo drives for 7.5 hours.
