For year 8 students, 20% have a shoe size greater than 10.5, but 95% have a shoe size less than 11.5. What is the chance of a year 8 student having a shoe size:

a. less than or equal to 10.5

b.11.5 or greater

c.between 10.5 and 11.5

i really dont know how to find the chances, please can someone explain to me how to do it??