Final answer:
The appropriate expression for the student's question about travel time is 120/x hours, if x denotes the travel rate in units per hour and the distance is 120 units. This conversion is based on the standard time calculation formula of dividing distance by rate.
Step-by-step explanation:
The question is asking to express the time required to complete the journey in terms of x, where x represents an unknown value related to time or speed. To approach this problem, we recall that when we are determining travel time, we use the formula time = distance/speed. In this context, if x is the speed (in units of distance per hour), then the time taken to complete a 120-unit distance journey would be calculated by dividing the distance by the speed, resulting in 120/x hours. This is under the assumption that x is not zero, as division by zero is undefined.
Now let's briefly overview unit conversions. To convert seconds to minutes, divide by 60, because there are 60 seconds in one minute. For example, 120 seconds is equal to 2 minutes. Similarly, to convert hours to minutes, multiply by 60, since there are 60 minutes in one hour. For instance, 4 hours is equal to 240 minutes.
When adding times, combine the like units and then convert if necessary. For example, 1 hour 55 minutes + 45 minutes equals 1 hour 100 minutes, which simplifies to 2 hours.
To summarize the student's question about the journey time: if the rate of travel is given by x and the distance is 120 units, the correct expression for the time to complete the journey is 120/x hours.