Part 1
Note that from 0 to 1 there are 3 spaces
To find out the value of each space
(1-0)/3=1/3
see the figure below to better understand the problem
Part 2
From 0 to 1 there are 5 spaces
so
(1-0)/5=1/5
see the figure below
Part 3
there are 6 spaces
so
(1-0)/6=1/6
see the figure below