Question

Two buses leave Dallas at the same time traveling in opposite directions. One bus travels at 59 mph and the other at 54 mph. How soon will they be 791 miles apart?

Answer 1

Let t be the time, in hours, elapsed till the buses are 791 miles apart, then we can set the following equation:

`59mph\cdot t+54\text{mph}\cdot t=791\text{ miles.}`

Solving the above equation for t we get:

`\begin{gathered} 113\text{ mph}\cdot t=791miles, \\ t=(791)/(113)\text{hours,} \\ t=7\text{ hours.} \end{gathered}`

Answer: 7 hours.