In how many ways can a student choose a programme of 5 course if 9 courses are available and 2 courses are compulsory for every student ?

Explanation

Out of available nine courses, two are compulsory. Hence the student is free to select 3 courses out of 7 remaining courses.
`therefore` The number of ways of selecting 3 courses out of 7 courses is
`.^(7)C_(3)=(7!)/((7-3)!3!)=(7!)/(4!3!)`
`=(7.6.5)/(3.2)=35` ways