First of all we will see how many 4 digit no we can have with and without rep. now the tenth place can have two options that is 0 and 5 so that the no is divisible by 5 let us call this first place now second place can have any no hence we have 8 options same logic with third place fourth place cannot have 0 so we have 7 options because if we do then we will have 3 digit no now take the product (7.8.8.2) when repetition is not allowed then (7.6.5.2)
(i) repetition allowed : 243 + 154 = 397 (ii) not allowed : 120+160 = 280