The number of four-digit odd numbers having digits 1,2,3,4 , each occurring exactly once, is:

Step-by-step solution

a b c d a b c d is odd number therefore d can take values as 1 or 3 2 posibility and a can take 3 value b can take 2 value c can take 1 value Total values =2 3 2 1 12 numbers