Problem 55235. Determine if x is a combination of m and n

There is a problem with the tests. Particularly with Test 20.
My solution kept failing the test until I changed the output to "False" always. At that point the solution passed.
Any feedback / suggestions would be appreciated.

@Lev: the line "combo=combo+1;" means that in some cases, the output can be > 1. All the other test cases just force-converted to logical so any nonzero numeric return will be T and 0 will be F. Test 20, however, actually checks against another logical, so the numerical return (>1) fails. The problem states that the function should return logical T/F, so there should probably be a test specifically for that.