Mike can ride his bike 15 miles per hour. How many miles could he reasonably ride in one day? \( \begin{array}{llll}\text { a. } 350 & \text { b. } 250 & \text { c. } 500 & \text { d. } 100\end{array} \)

Mike rides at a constant speed of \(15\) miles per hour. To estimate how far he could ride in one day, we must consider a reasonable number of hours that he could actually be biking. While one day has \(24\) hours, it is not realistic to bike continuously without breaks for eating, resting, or sleeping. A typical long bike ride might last between \(5\) and \(7\) hours. For example, if Mike rides for \(7\) hours, the distance he would cover is \[ 15 \text{ miles/hour} \times 7 \text{ hours} = 105 \text{ miles}. \] This estimate is close to \(100\) miles, which is a reasonable distance to cover in a day considering the need for rest and other breaks. Thus, among the given options \[ \begin{array}{llll} \text{a. } 350 & \text{b. } 250 & \text{c. } 500 & \text{d. } 100 \end{array} \] the best choice is \[ \text{d. } 100. \]