One student begins in cleveland, ohio, and walks towards buffalo, new york, a distance of 200 miles. she walks at the rate of 2.5 miles per hour. another student begins riding his bicycle in cleveland and rides towards buffalo at the rate of 11 miles per hour. the walking student begins her journey at 8: 00 am. the riding student starts 4 hours later.

The problem did not have enough details.It seems like you want to know that  !st person leaves and 2nd person leaves; how long before they catch up together? These types of problems are called Uniform Motion or Rate-Time-Distance.There is a good video for you to watch.Similar to the problem you need help with. Yourmathgal channel on Youtube,she is a teacher.Have watched a lot of her videos.Watch the video on her channel called "Rate-Time-Distance Intro".It is 10:40 and she explains the 6 kinds of Uniform Motion problems.