A. The three sides of a right-angled triangle have integral lengths and also form an arithmetic progression. A possible length of one of the sides is?B. The question paper of an examination comprises three sections of 7, 6 and 5 questions respectively. A total of 15 questions are to be answered, with a minimum of three questions to be answered in each section. Also the number of questions answered from the second section shall be more than those answered from each of the remaining two sections. In how many different ways can a candidate choose to answer the required total of 15 questions from among the three sections?