Example 22.3 

 The no of free paths which are longer than, 
 10 cm = 3679,
 20 cm = 1354,
 50 cm = 68,

 The no of free paths which are between,
 5 cm and 10 cm = -2387,
 9.5 cm and 10.5 cm = -369,
 9.9 cm and 10.1 cm = -74,

 The no of free paths which are exactly 10 cm = 0