In how many different ways can 6 runners be assigned to 6 lanes at the start of a race?

Well you have runner 1 in lane 1. runner 1 in lane 2 and so on. so it becomes 1,1 1,2 1,3 1,4 1,5 1,6 and then 2,1 2,2 2,3 2,4 2,5 2,6 then 3, and so on

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's

In this problem it decreased 20%