Let f:[0,3]→R be defined by f(x)=min{x−[x],1+[x]−x} where [x] is the greatest integer less than or equal to x . Let P denote the set containing all x∈[0,3] where f is discontinuous, and Q denote the set containing all x∈(0,3) where f is not differentiable. Then the sum of number of elements in P and Q is equal to
(a) 5
(b) 3
(c) 6
(d) 2