I would go with E

(Y)(M) = (X)(K) (a)

1. If x is a factor of Y, then we still do not know anything about M and K. Insuff.

2. It is not enough to know that K is less than or equal to M. We need to know if k is a "factor" of M.

1 + 2 . No additional info. E

I also used numbers that matched the conditions given in both 1 & 2. For example.

Is (4) (8) = (2) (7) (a)

Here is clear that x is a factor of Y and K is less than M. but Xk is not a factor of YM.

I'd go with E w/o even testing any numbers.

IMO E as well.

Xbond wrote:Hi there,

Could you explain in the simplest this concept and how to resolve it


x, y, k, m are positive integers, is xk a factor of ym ?
(1) x is a factor of y
(2) k <= m

restate: is ym/xk=integer

s1) y/x=integer but that doesn't resolve m and k insufficient.
s2) k could be equal to m or less than m but that doesn't resolve y and x...
s1+s2) y and x is sorted out but m and k are not. m could equal k, which would give us answer yes. but m could also be greater than k, which would us answer no. insufficient.

therefore E

you got this man!