p=log32/9=2/5 * log2/3-------5p/2=lg3/lg2 q=log27/25=2/3 * log3/5-------3q/2=lg5/lg3 2/5p=lg2/lg3 2/5p+3q/2=lg10/lg3=1/lg3 lg3=10p/(4+15pq) lg5=3q/2 *lg3=3q/2 * [10p/(4+15pq)]=15pq/(4+15pq)