1) Jack and Jill ran a 100 meter race. Jill ran the race in 10 seconds and won by 10 meters; Jack had run only 90 meters when Jill crossed the finish line. They decide to race again, but this time Jill starts 10 meters behind the starting line. Assuming that both runners run at the same pace as before, who will will the second race and by how many seconds?
2) It takes you 60 seconds to walk from the first (ground) floor of a building to the fourth floor. How long will it take to walk from the first floor to the eighth floor (at the same pace, assuming all floors have the same height)?
3) Suppose you have a pipe with a circumference 6 cm and length 20 cm and that 10 turns of a wire are wrapped around the pipe. What is the length of the wire?