MathDB

a+b+c+d=21... isi(bs) 2010 #2

Source:

May 16, 2012

modular arithmetic

Problem Statement

Let

a,b,c,d

be distinct digits such that the product of the

2

-digit numbers

\overline{ab}

and

\overline{cb}

is of the form

\overline{ddd}

. Find all possible values of

a+b+c+d