2021 JMPSC Accuracy Problems/Problem 1
Problem
Find the sum of all positive multiples of
that are factors of
Solution
We use the fact that
and
to conclude that the only multiples of
that are factors of
are
,
, and
. Thus, our answer is
.
~Bradygho
Solution 2
The factors of
are
,
,
and
. Out of these, only
,
and
are multiples of
, so the answer is
.