Let's say you have this data: 25, 26, 24, 26, 25, 7, 8, 8, 15, 10, 25, 24, 26 What should your bin size be if you want to have 10 bins

Your bin size should be 2

Ok so let T=time from when Tim starts
Distance Tim travels= T*90
Distance Dora travels=T*75 + 75  (<as already started)
for him to have caught up His distance must equal hers so:
90T=75T + 75  (now minus 75T)
15T=75  (now divide by 15)
T=5 :)
So five hourse, hope this helped :)