There are 3 sections in a question paper and each section contains 5 questions. A candidate has to answer a total of 5 questions, choosing at least one question from each section. Then the number of ways, in which the candidate can choose the questions, is:

A(5)                  B(5)         C(5)           113131311221212122 Number of ways to choose,(1,1,3) or (1,3,1) or (3,1,1) questions from A, B, C = C1 x C1  5 x C3  5  5 x 3 =750 ways(2,2,1) or (2,1,2) or (1,2,2) questions from A, B, C = C2 x C2  5 x C1  5  5 x 3 = 1500 waysHence, the total number ways = 2250