Question 698150
The Grocer's price is {{{ a/b }}} ( pounds of butter ) / ( cents )
and
[ {{{ x }}} ( pounds of butter )] / [{{{ a/b }}}  ( pounds of butter ) / ( cents )]
= [{{{ (b/a)*x }}} ( cents/pounds of butter )]*(pounds of butter )
= {{{ b*x/a }}} cents