Question 1021418
{{{67184=2^4*13*17*19}}}
{{{A*B*C*D=67184}}}
{{{D-A=30}}}
{{{19<B<C<D<40}}}
{{{13<=A<=19}}}
Given the factorization of 67184, the teenager can only be 13, 16, 17, or 19.
However since {{{D=A+30}}}, then D is either 43, 46, 47 or 49, which violates that the oldest is less than 40. 
Please clarify and repost your question.