Part of me is saying multiply the 8 by 60 to get minutes, add the extra 15 and you have 495 mins. Divide this by 60 and you get 8.25%. The other part of me is saying divide by 100 and get 4.95. If you divide 60 by 4.95 you then get 12.12 so this answer is 12.12% which I am struggling to turn into a fraction. Then I argue reason in my head saying if the original journey only took 8 hours instead of 8:15hrs 15 mins, I hour would clearly be one 8th so the answer can't possibly be 12.12%

Can someone please help? I would appreciate someone explaining what I am doing wrong, so I can learn rather than just tell me the answer if thats ok. Its such a simple thing and I have got myself really confused. Thank you for taking the time to read this post and hopefully helping. I hope I have posted it into the right section.