Question 346959
There was a misunderstanding with the previous answer.   For the question, A, B, C & D represent 4 different numbers and the multiplication of number AB with number CD results in a number DDD.   


The key to solving this problem is to recognize that DDD has factors of D and 111.
In turn, 111 has factors 3 and 37. 


Stop reading now as you may be able to solve with that clue.




Did you get it?   


To continue (DDD) = (37 * 3 * D ) = (AB * CD) 

Thus can infer that either AB or CD is 37 and the other number is D * 3.

Using guess and check to find D and we get 5 and 7 as possible value of D.

So, ensuring that the digit value of the second number is D ...

D=5:    

37 * 3 * 5 = 555
37 * 15 = 555
A=3, B=7, C=1, D=5

and

D=7:    

37 * 3 * 7 = 777
21 * 37 = 777
A=2, B=1, C=3, D=7