Since the number 6545 ends in a 5, we can assume that one of the two digit numbers ends in a 5. I tried 55, 65, 75, and 85, and I just divided 6545 by those numbers until I got a two-digit positive integer as my answer,
Since each trip takes 1 km, we multiply 23 by 1 to get 23 km in total. We then add this onto the 1 km that she has already walked to get 24 km as our answer.
