The number  of  5  digit  numbers  which  are  divisible  by  4,  with  digits  from  the  set{1, 2, 3, 4, 5} and the repetition of digits is allowed, is          .

Option for last two digits are (12), (24), (32), (44) are (52).  And the first three digits can be filled in 5×5×5 ways since repitition is  allowed. Hence  total No. of digits       = 5 × 5 × 5 × 5 = 625