SOLUTION: In how many ways can a student select five questions to answer from an exam containing nine questions if the student is required to answer the first and the last question?

Student should select five questions to answer, but of these five questions, two of them,
the first and the last questions, are obligatory: they are not the subject of choice.


It means that the student really selects only 5-2 = 3 questions from 9-2 = 7 questions.


The number of way to select 3 questions from 7 questions is  

     =  = 35.


ANSWER. In 35 ways.