2 sec. Fold into two feet each in zigzag manner. Cut in middle so you will be left with 2 one feet ribbon and 49 of 2 feet ribbons. Stack 49 of 2 feet ribbons and cut in middle.

One dog and one cat

Let’s assume one way distance to be x km
1. In first scenario, Kevin drives 90km and Daniel x-90km
2. In return, Daniel drives 100km so Kevin will get to drive x-100km

So in total Kevin drives x-10km (90+x-100) and Daniel drives x+10km (x-90+100). So Daniel drives 20km more than Kevin.